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Reverse Reaction (reverse + reaction)
Selected AbstractsIsoprenoid biosynthesis in plants , 2C -methyl- d -erythritol-4-phosphate synthase (IspC protein) of Arabidopsis thalianaFEBS JOURNAL, Issue 19 2006Felix Rohdich The ispC gene of Arabidopsis thaliana was expressed in pseudomature form without the putative plastid-targeting sequence in a recombinant Escherichia coli strain. The recombinant protein was purified by affinity chromatography and was shown to catalyze the formation of 2C -methyl- d -erythritol 4-phosphate from 1-deoxy- d -xylulose 5-phosphate at a rate of 5.6 µmol·min,1·mg,1 (kcat 4.4 s,1). The Michaelis constants for 1-deoxy- d -xylulose 5-phosphate and the cosubstrate NADPH are 132 and 30 µm, respectively. The enzyme has an absolute requirement for divalent metal ions, preferably Mn2+ and Mg2+, and is inhibited by fosmidomycin with a Ki of 85 nm. The pH optimum is 8.0. NADH can substitute for NADPH, albeit at a low rate (14% as compared to NADPH). The enzyme catalyzes the reverse reaction at a rate of 2.1 µmol·min -1·mg -1. [source] Two beta-alanyl-CoA:ammonia lyases in Clostridium propionicumFEBS JOURNAL, Issue 3 2005Gloria Herrmann The fermentation of ,-alanine by Clostridium propionicum proceeds via activation to the CoA-thiol ester, followed by deamination to acryloyl-CoA, which is also an intermediate in the fermentation of l -alanine. By shifting the organism from the carbon and energy source ,-alanine to ,-alanine, the enzyme ,-alanyl-CoA:ammonia lyase is induced 300-fold (, 30% of the soluble protein). The low basal lyase activity is encoded by the acl1 gene, whereas the almost identical acl2 gene (six amino acid substitutions) is responsible for the high activity after growth on ,-alanine. The deduced ,-alanyl-CoA:ammonia lyase proteins are related to putative ,-aminobutyryl-CoA ammonia lyases involved in lysine fermentation and found in the genomes of several anaerobic bacteria. ,-Alanyl-CoA:ammonia lyase 2 was purified to homogeneity and characterized as a heteropentamer composed of 16 kDa subunits. The apparent Km value for acryloyl-CoA was measured as 23 ± 4 µm, independent of the concentration of the second substrate ammonia; kcat/Km was calculated as 107 m,1·s,1. The apparent Km for ammonia was much higher, 70 ± 5 mm at 150 µm acryloyl-CoA with a much lower kcat/Km of 4 × 103 m,1·s,1. In the reverse reaction, a Km of 210 ± 30 µM was obtained for ,-alanyl-CoA. The elimination of ammonia was inhibited by 70% at 100 mm ammonium chloride. The content of ,-alanyl-CoA:ammonia lyase in ,-alanine grown cells is about 100 times higher than that required to sustain the growth rate of the organism. It is therefore suggested that the enzyme is needed to bind acryloyl-CoA, in order to keep the toxic free form at a very low level. A formula was derived for the calculation of isomerization equilibra between l -alanine/,-alanine or d -lactate/3-hydroxypropionate. [source] Identification, purification and characterization of an acetoacetyl-CoA thiolase from rat liver peroxisomesFEBS JOURNAL, Issue 10 2000Vasily D. Antonenkov Acetoacetyl-CoA specific thiolases catalyse the cleavage of acetoacetyl-CoA into two molecules of acetyl-CoA and the synthesis (reverse reaction) of acetoacetyl-CoA. The formation of acetoacetyl-CoA is the first step in cholesterol and ketone body synthesis. In this report we describe the identification of a novel acetoacetyl-CoA thiolase and its purification from isolated rat liver peroxisomes by column chromatography. The enzyme, which is a homotetramer with a subunit molecular mass of 42 kDa, could be distinguished from the cytosolic and mitochondrial acetoacetyl-CoA thiolases by its chromatographic behaviour, kinetic characteristics and partial internal amino-acid sequences. The enzyme did not catalyse the cleavage of medium or long chain 3-oxoacyl-CoAs. The enzyme cross-reacted with polyclonal antibodies raised against cytosolic acetoacetyl-CoA thiolase. The latter property was exploited to confirm the peroxisomal localization of the novel thiolase in subcellular fractionation experiments. The peroxisomal acetoacetyl-CoA thiolase most probably catalyses the first reaction in peroxisomal cholesterol and dolichol synthesis. In addition, its presence in peroxisomes along with the other enzymes of the ketogenic pathway indicates that the ketogenic potential of peroxisomes needs to be re-evaluated. [source] Ab initio chemical kinetics for the NH2 + HNOx reactions, part II: Kinetics and mechanism for NH2 + HONOINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 11 2009Shucheng Xu The kinetics and mechanism for the reaction of NH2 with HONO have been investigated by ab initio calculations with rate constant prediction. The potential energy surface of this reaction has been computed by single-point calculations at the CCSD(T)/6-311+G(3df, 2p) level based on geometries optimized at the CCSD/6-311++G(d, p) level. The reaction producing the primary products, NH3 + NO2, takes place via precomplexes, H2N,,,c -HONO or H2N,,,t -HONO with binding energies, 5.0 or 5.9 kcal/mol, respectively. The rate constants for the major reaction channels in the temperature range of 300,3000 K are predicted by variational transition state theory or Rice,Ramsperger,Kassel,Marcus theory depending on the mechanism involved. The total rate constant can be represented by ktotal = 1.69 × 10,20 × T2.34 exp(1612/T) cm3 molecule,1 s,1 at T = 300,650 K and 8.04 × 10,22 × T3.36 exp(2303/T) cm3 molecule,1 s,1 at T = 650,3000 K. The branching ratios of the major channels are predicted: k1 + k3 producing NH3 + NO2 accounts for 1.00,0.98 in the temperature range 300,3000 K and k2 producing OH + H2NNO accounts for 0.02 at T > 2500 K. The predicted rate constant for the reverse reaction, NH3 + NO2 , NH2 + HONO represented by 8.00 × 10,26 × T4.25 exp(,11,560/T) cm3 molecule,1 s,1, is in good agreement with the experimental data. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 678,688, 2009 [source] Rate constants for H + CH4, CH3 + H2, and CH4 dissociation at high temperatureINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 11 2001J. W. Sutherland The Laser Photolysis-Shock Tube technique coupled with H-atom atomic resonance absorption spectrometry has been used to study the reaction, H + CH4 , CH3 + H2, over the temperature range, 928,1697 K. Shock-tube studies on the reverse of this reaction, CH3 + H2 , H + CH4, using CH3I dissociation in the presence of H2 yielded H-atom formation rates and rate constants for the reverse process over the temperature range, 1269,1806 K. These results were transformed (using well-established equilibrium constants) to the forward direction. The combined results for H + CH4 can be represented by an experimental three parameter expression, k = 6.78 × 10,21 T3.156 exp(,4406 K/T) cm3 molecule,1 s,1 (348,1950 K) that was evaluated from the present work and seven previous studies. Using this evaluation, disagreements between previously reported values for the dissociation of CH4 could be reconciled. The thermal decomposition of CH4 was then studied in Kr bath gas. The dissociation results agreed with the earlier studies and were theoretically modeled with the Troe formalism. The energy transfer parameter necessary to explain both the present results and those of Kiefer and Kumaran (J Phys Chem 1993, 97, 414) is, ,,,E,all/cm,1 = 0.3323 T0.7. The low temperature data on the reverse reaction, H + CH3 (in He) from Brouard et al. (J Phys Chem 1989, 93, 4047) were also modeled with the Troe formalism. Lastly, the rate constant for H + CH4 was theoretically calculated using conventional transition state theory with Eckart tunneling corrections. The potential energy surface used was from Kraka et al. (J Chem Phys 1993, 99, 5306) and the derived T-dependence with this method agreed almost perfectly with the experimental evaluation. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 669,684, 2001 [source] Cutting Long Syntheses Short: Access to Non-Natural Tyrosine Derivatives Employing an Engineered Tyrosine Phenol LyaseADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 4 2010Birgit Seisser Abstract The chemical synthesis of 3-substituted tyrosine derivatives requires a minimum of four steps to access optically enriched material starting from commercial precursors. Attempting to short-cut the cumbersome chemical synthesis of 3-substituted tyrosine derivatives, a single step biocatalytic approach was identified employing the tyrosine phenol lyase from Citrobacter freundii. The enzyme catalyses the hydrolysis of tyrosine to phenol, pyruvate and ammonium as well as the reverse reaction, thus the formation of tyrosine from phenol, pyruvate and ammonium. Since the wild-type enzyme possessed a very narrow substrate spectrum, structure-guided, site-directed mutagenesis was required to change the substrate specificity of this CC bond forming enzyme. The best variant M379V transformed, for example, o -cresol, o -methoxyphenol and o -chlorophenol efficiently to the corresponding tyrosine derivatives without any detectable side-product. In contrast, all three phenol compounds were non-substrates for the wild-type enzyme. Employing the mutant, various L -tyrosine derivatives (3-Me, 3-OMe, 3-F, 3-Cl) were obtained with complete conversion and excellent enantiomeric excess (>97%) in just a single ,green' step starting from pyruvate and commercially available phenol derivatives. [source] Kinetic study on the prooxidative effect of vitamin C on the autoxidation of glycerol trioleate in micellesJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 2 2006Zai-Qun Liu Abstract Vitamin C (L -ascorbic acid) protects human health by scavenging toxic free radicals and other reactive oxygen species formed in cell metabolism. The surplus supplementation of vitamin C, however, may be harmful to health because the level of 8-oxoguanine and 8-oxoadenine in lymphocyte DNA varies remarkably. In the process of the kinetic investigation on the 2,2,-azobis(2-amidinopropane dihydrochloride) (AAPH)-induced autoxidation of glycerol trioleate (GtH) in the micelles of cetyl trimethyl ammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and Triton X-100, the addition of vitamin C accelerates the autoxidation of GtH even in the absence of the free radical initiator, AAPH. The initiating rate, Ri, of vitamin C (VC)-induced autoxidation of GtH is related to the micelle charge, i.e. Ri,=,14.4,×,10,6 [VC] s,1 in SDS (anionic micelle), Ri,=,1961,×,10,6 [VC] s,1 in Triton X-100 (neutral micelle) and Ri is a maximum in CTAB (cationic micelle) when the vitamin C concentration is ,300,µM. Thus, vitamin C can initiate autoxidation of GtH in micelles, especially in the neutral one. Moreover, the attempt to explore whether ,-tocopherol (TocH) could rectify vitamin C-induced autoxidation of GtH leads us to find that the rate constant of TocH reacting with the anionic radical of vitamin C (VC.,), k,inh, is ,103M,1,s,1, which is less than that of the ,-tocopherol radical (Toc.) with vitamin C (kinh,=,,105,M,1,s,1). Thus, the equilibrium constant of the reaction Toc.+VC,,TocH+VC., is prone strongly to the regeneration of Toc. by vitamin C rather than the reverse reaction. Copyright © 2006 John Wiley & Sons, Ltd. [source] Hairpin telomeres and genome plasticity in Borrelia: all mixed up in the endMOLECULAR MICROBIOLOGY, Issue 3 2005George Chaconas Summary Spirochetes of the genus Borrelia have a highly unusual genome structure composed of over 20 replicons. Most of these replicons are linear and terminated by covalently closed hairpin ends or telomeres. Moreover, the linear replicons are affected by extensive DNA rearrangements, including telomere exchanges, DNA duplications, and harbour a large number of pseudogenes. The mechanism for the unusual genome plasticity in the linear replicons has remained elusive. The enzymatic machinery (the telomere resolvase ResT) responsible for generating the hairpin ends from replicative intermediates has recently been shown to also perform a reverse reaction that fuses telomeres on unrelated replicons. Infrequent stabilization of such fusion events over evolutionary time provides the first proposed biochemical mechanism for the DNA rearrangements that are so prominent in the linear replicons of B. burgdorferi. [source] The active site of hydroxynitrile lyase from Prunus amygdalus: Modeling studies provide new insights into the mechanism of cyanogenesisPROTEIN SCIENCE, Issue 2 2002Ingrid Dreveny Abstract The FAD-dependent hydroxynitrile lyase from almond (Prunus amygdalus, PaHNL) catalyzes the cleavage of R -mandelonitrile into benzaldehyde and hydrocyanic acid. Catalysis of the reverse reaction,the enantiospecific formation of ,-hydroxynitriles,is now widely utilized in organic syntheses as one of the few industrially relevant examples of enzyme-mediated C,C bond formation. Starting from the recently determined X-ray crystal structure, systematic docking calculations with the natural substrate were used to locate the active site of the enzyme and to identify amino acid residues involved in substrate binding and catalysis. Analysis of the modeled substrate complexes supports an enzymatic mechanism that includes the flavin cofactor as a mere "spectator" of the reaction and relies on general acid/base catalysis by the conserved His-497. Stabilization of the negative charge of the cyanide ion is accomplished by a pronounced positive electrostatic potential at the binding site. PaHNL activity requires the FAD cofactor to be bound in its oxidized form, and calculations of the pKa of enzyme-bound HCN showed that the observed inactivation upon cofactor reduction is largely caused by the reversal of the electrostatic potential within the active site. The suggested mechanism closely resembles the one proposed for the FAD-independent, and structurally unrelated HNL from Hevea brasiliensis. Although the actual amino acid residues involved in the catalytic cycle are completely different in the two enzymes, a common motif for the mechanism of cyanogenesis (general acid/base catalysis plus electrostatic stabilization of the cyanide ion) becomes evident. [source] Structure of the C subunit of V-type ATPase from Thermus thermophilus at 1.85,Å resolutionACTA CRYSTALLOGRAPHICA SECTION D, Issue 5 2004Nobutaka Numoto The V-type H+ -ATPases are similar to the F-type ATP synthases in their structure and functional mechanism. They hydrolyze ATP coupled with proton translocation across a membrane, but in some archaea and eubacteria they also synthesize ATP in the reverse reaction. The C subunit is one of the components of the membrane-bound V0 moiety of V-type ATPases. The C subunit of V-type H+ -ATPase from Thermus thermophilus was crystallized in a monoclinic form and its crystal structure was determined at 1.85,Å resolution by the MAD method using selenomethionyl protein. The structure has a cone (tapered cylinder) shape consisting of only two types of helix (long and short) as secondary-structure elements. The molecule is divided into three similar domains, each of which has essentially the same topology. On the basis of the structural features and molecular-surface charge distribution, it is suggested that the bottom side of the C subunit is a possible binding site for the V0 proteolipid L-subunit ring and that the C subunit might function as a spacer unit between the proteolipid L-subunit ring and the rotating V1 central shaft. [source] Crystallization of mitochondrial rhodoquinol-fumarate reductase from the parasitic nematode Ascaris suum with the specific inhibitor flutolanilACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 9 2009Arihiro Osanai In adult Ascaris suum (roundworm) mitochondrial membrane-bound complex II acts as a rhodoquinol-fumarate reductase, which is the reverse reaction to that of mammalian complex II (succinate-ubiquinone reductase). The adult A. suum rhodoquinol-fumarate reductase was crystallized in the presence of octaethyleneglycol monododecyl ether and n -dodecyl-,- d -maltopyranoside in a 3:2 weight ratio. The crystals belonged to the orthorhombic space group P212121, with unit-cell parameters a = 123.75, b = 129.08, c = 221.12,Å, and diffracted to 2.8,Å resolution using synchrotron radiation. The presence of two molecules in the asymmetric unit (120,kDa × 2) gives a crystal volume per protein mass (VM) of 3.6,Å3,Da,1. [source] Factors Mediating Activity, Selectivity, and Substrate Specificity for the Thiamin Diphosphate-Dependent Enzymes Benzaldehyde Lyase and Benzoylformate DecarboxylaseCHEMBIOCHEM, Issue 12 2006Michael Knoll Abstract Benzaldehyde lyase from Pseudomonas fluorescens and benzoylformate decarboxylase from Pseudomonas putida are homologous thiamin diphosphate-dependent enzymes that catalyze carboligase and carbolyase reactions. Both enzymes catalyze the formation of chiral 2-hydroxy ketones from aldehydes. However, the reverse reaction has only been observed with benzaldehyde lyase. Whereas benzaldehyde lyase is strictly R specific, the stereoselectivity of benzoylformate decarboxylase from P. putida is dependent on the structure and orientation of the substrate aldehydes. In this study, the binding sites of both enzymes were investigated by using molecular modelling studies to explain the experimentally observed differences in the activity, stereo- and enantioselectivity and substrate specificity of both enzymes. We designed a detailed illustration that describes the shape of the binding site of both enzymes and sufficiently explains the experimental effects observed with the wild-type enzymes and different variants. These findings demonstrate that steric reasons are predominantly responsible for the differences observed in the (R)-benzoin cleavage and in the formation of chiral 2-hydroxy ketones. [source] Metal-Mediated Formation of Carbon,Halogen BondsCHEMISTRY - A EUROPEAN JOURNAL, Issue 17 2008Arkadi Vigalok Prof. Dr. Abstract Organic halides represent basic starting materials for numerous metal-catalyzed organic transformations. Generally, the carbon,halogen is broken in the first step, that is, an oxidative addition reaction, of the catalytic cycle. On the other hand, very little is known about the reverse reaction, carbon,halogen reductive elimination from a transition-metal center. In this Concept article, we describe the examples of C(sp3)halide and C(sp2)halide reductive-elimination reactions which demonstrate that this type of reactivity can be quite common in organometallic chemistry. Although the thermodynamic driving force for the formation of carbon,halogen bonds is relatively small, the kinetic barrier for these reactions can also be low. Thus, Chalide reductive elimination can compete favorably with the more established organic transformations, such as CC reductive elimination. [source] Nucleophilicities and Nucleofugalities of Organic Carbonates,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 22 2010Nicolas Streidl Abstract The kinetics of the reactions of the methyl carbonate ion with benzhydrylium ions in acetonitrile have been studied by UV/Vis spectrophotometry. Substitution of the resulting second-order rate constants and the electrophilicity parameters E of the benzhydrylium ions into the linear free energy relationship log,k = s(N + E) yielded the nucleophilicity parameters N25 = 16.03 and s25 = 0.64 for methyl carbonate in acetonitrile. The kinetics of the reverse reactions, i.e., of the solvolyses of ring-substituted benzhydryl alkyl carbonates in different aqueous solvents were followed by conductimetry. The obtained first-order rate constants and the known electrofugality parameters Ef of benzhydrylium ions were used to determine the nucleofugality parameters Nf and sf of the ROCO2, groups by using the linear free energy relationship log,k = sf(Nf + Ef). The leaving group abilities of carbonates decrease by a factor of about 300 from PhOCO2, over MeOCO2, and iBuOCO2, to tBuOCO2, in various alcoholic and aqueous solvents. tert -Butyl carbonates (tBocO-R) are, thus, considerably more stable with respect to heterolytic cleavage of the O,R bond than other organic carbonates. [source] Kinetic isotope effects for the H2 + C2H , C2H2 + H reaction based on the ab initio calculations and a global potential energy surfaceINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 5 2010Liping Ju In the present paper, kinetic isotope effects of the title reaction are studied with canonical variational transition state theory on the modified Wang Bowman (MWB) potential energy surface (PES) (Chem Phys Lett 2005, 409, 249) and the ab initio calculations at the quadratic configuration interaction (QCISD (T, full))/aug-cc-pVTZ//QCISD (full)/cc-pVTZ level. The calculated rate constants for the isotopic variants of this title reaction on the MWB PES have good agreement with those of the present ab initio calculations over the temperature range of 20,5000 K for the forward reactions and 800,5000 K for the reverse reactions, respectively. In particular, the forward rate constants for the title reaction and its isotopically substituted reactions have negative temperature dependences at about 40 K. Rate expressions are presented for all the studied reactions. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 289,298, 2010 [source] Exploring the use of multiple analogical models when teaching and learning chemical equilibriumJOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 10 2005Allan G. Harrison This study describes the multiple analogical models used to introduce and teach Grade 12 chemical equilibrium. We examine the teacher's reasons for using models, explain each model's development during the lessons, and analyze the understandings students derived from the models. A case study approach was used and the data were drawn from the observation of three consecutive Grade 12 lessons on chemical equilibrium, pre- and post-lesson interviews, and delayed student interviews. The key analogical models used in teaching were: the "school dance"; the "sugar in a teacup"; the "pot of curry"; and the "busy highway." The lesson and interview data were subject to multiple, independent analyses and yielded the following outcomes: The teacher planned to use the students' prior knowledge wherever possible and he responded to student questions with stories and extended and enriched analogies. He planned to discuss where each analogy broke down but did not. The students enjoyed the teaching but built variable mental models of equilibrium and some of their analogical mappings were unreliable. A female student disliked masculine analogies, other students tended to see elements of the multiple models in isolation, and some did not recognize all the analogical mappings embedded in the teaching plan. Most students learned that equilibrium reactions are dynamic, occur in closed systems, and the forward and reverse reactions are balanced. We recommend the use of multiple analogies like these and insist that teachers always show where the analogy breaks down and carefully negotiate the conceptual outcomes. © 2005 Wiley Periodicals, Inc. J Res Sci Teach 42: 1135,1159, 2005 [source] HD in the primordial gasMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2000D. R. Flower We study the role of HD in the thermal balance of the primordial gas, beyond the redshift, z, at which the temperatures of radiation and matter have decoupled (z , 300). Statistical arguments are used to derive the rate constants for the forward and reverse reactions, D+(H2, HD)H+, involving reactant and product molecules in excited rotational states. The degree of chemical fractionation of HD is enhanced, compared with the value calculated by taking account of reactions between ground-state molecules only, by a factor of about 2. In spite of its low abundance (10,3), relative to H2, HD contributes comparably to the rate of heating of the gas, through rotationally inelastic collisions with H and He. The much larger rate coefficients for collisional population transfer within HD, compared with H2, and the tighter rotational level spacing are responsible for this finding. We conclude that HD is about as important as H2 in the thermal balance of the primordial gas. [source] Preparation of Core,Shell-Structured Nanoparticles (with a Noble-Metal or Metal Oxide Core and a Chromia Shell) and Their Application in Water Splitting by Means of Visible LightCHEMISTRY - A EUROPEAN JOURNAL, Issue 26 2010Kazuhiko Maeda Dr. Abstract Core,shell-structured nanoparticles, consisting of a noble metal or metal oxide core and a chromia (Cr2O3) shell, were studied as promoters for photocatalytic water splitting under visible light. Core nanoparticles were loaded by impregnation, adsorption or photodeposition onto a solid solution of gallium nitride and zinc oxide (abbreviated GaN:ZnO), which is a particulate semiconductor photocatalyst with a band gap of approximately 2.7,eV, and a Cr2O3 shell was formed by photodeposition using a K2CrO4 precursor. Photodeposition of Cr2O3 on GaN:ZnO modified with a noble metal (Rh, Pd and Pt) or metal oxide (NiOx, RuO2 and Rh2O3) co-catalyst resulted in enhanced photocatalytic activity for overall water splitting under visible light (,>400,nm). This enhancement in activity was primarily due to the suppression of undesirable reverse reactions (H2,O2 recombination and/or O2 photoreduction) and/or protection of the core component from chemical corrosion, depending on the core type. Among the core materials examined, Rh species exhibited relatively high performance for this application. The activity for visible-light water splitting on GaN:ZnO modified with an Rh/Cr2O3 core,shell configuration was dependent on both the dispersion of Rh nanoparticles and the valence state. In addition, the morphology of the Cr2O3 photodeposits was significantly affected by the valence state of Rh and the pH at which the photoreduction of K2CrO4 was conducted. When a sufficient amount of K2CrO4 was used as the precursor and the solution pH ranged from 3 to 7.5, Cr2O3 was successfully formed with a constant shell thickness (,2,nm) on metallic Rh nanoparticles, which resulted in an effective promoter for overall water splitting. [source] | ||||||||||||||||||||||