Chlorobenzene is a model molecule for researching harmful chlorinated volatile organic compounds.Designing the chemical adsorption site for complex molecules such as chlorobenzene is challenging without a large datase...Chlorobenzene is a model molecule for researching harmful chlorinated volatile organic compounds.Designing the chemical adsorption site for complex molecules such as chlorobenzene is challenging without a large dataset and reasonable descriptors.Here,the adsorption of chlorobenzene on a phosphorylated CeO_(2)catalyst was analyzed using density functional theory calculations.Three different surface phosphate(H_(x)PO_(4))models were constructed and used to adsorb chlorobenzene.An orbital interaction with fully occupied antibonding is found in one of three physical adsorptions.Based on this,the surface sites of a tri-cluster(M_(3))located at the CeO_(2)surface have been suggested to activate chlorobenzene.Three different clusters have been tested,namely Fe_(3),Ru_(3),and B_(3).All these clusters can activate and twist chlorobenzene by donating electrons.Fe_(3)and Ru_(3)form bonds with weak covalent and strong ionic characters,while B3forms strong covalent bonds between boron and carbon.This work not only predicts a class of sites for chlorobenzene activation that may prevent polychlorinated by-products but also gives a template for catalyst rational design according to fundamental catalytic theory.展开更多
The atomic structure of the active sites in Cu/CeO2 catalysts is intimately associated with the copper-ceria interaction. Both the shape of ceria and the loading of copper affect the chemical bonding of copper species...The atomic structure of the active sites in Cu/CeO2 catalysts is intimately associated with the copper-ceria interaction. Both the shape of ceria and the loading of copper affect the chemical bonding of copper species on ceria surfaces and the electronic and geometric character of the relevant interfaces. Nanostructured ceria, including particles(polyhedra), rods, and cubes, provides anchoring sites for the copper species. The atomic arrangements and chemical properties of the(111),(110) and(100) facets, preferentially exposed depending on the shape of ceria, govern the copper-ceria interactions and in turn determine their catalytic properties. Also, the metal loading significantly influences the dispersion of copper species on ceria with a specific shape, forming copper layers, clusters, and nanoparticles. Lower copper contents result in copper monolayers and/or bilayers while higher copper loadings lead to multi-layered clusters and faceted particles. The active sites are usually generated via interactions between the copper atoms in the metal species and the oxygen vacancies on ceria, which is closely linked to the number and density of surface oxygen vacancies dominated by the shape of ceria.展开更多
The presence of alkali metals in exhaust gas from stationary resources causes a grand challenge for the practical application of selective catalytic reduction(SCR)of NO_(x) with NH_(3).Here,alkali-resistant NO_(x) red...The presence of alkali metals in exhaust gas from stationary resources causes a grand challenge for the practical application of selective catalytic reduction(SCR)of NO_(x) with NH_(3).Here,alkali-resistant NO_(x) reduction has been successfully implemented via tailoring the electron transfer over Fe and V species on FeVO_(4)/TiO_(2)catalysts.The strong interaction between Fe and V induced electron transfer from V to Fe and strengthened the adsorption and activation of NH_(3)and NO over active VO_(x) sites.In the presence of K_(2)O,the strong electron withdrawing effect of Fe offset the electron donating effect of K on the VO_(x) species,thus protecting the active species VO_(x) to maintain the NO_(x) reduction ability.The enhanced adsorption and activation of NH_(3) allowed SCR reaction to proceed via E-R mechanism even after K_(2)O poisoning.This work elucidated the electronic effects on the alkali metals resistance of traditional ferric vanadate SCR catalysts and provided a promising strategy to design SCR catalysts with superior alkali resistance.展开更多
Metal oxides have been used as the supports for heterogeneous catalysis formany years,but they still suffer from coking in some high-temperature applications.The main reasons for coking are the uncontrollable dissocia...Metal oxides have been used as the supports for heterogeneous catalysis formany years,but they still suffer from coking in some high-temperature applications.The main reasons for coking are the uncontrollable dissociation of C-H and the overbalance between carbon deposition and removal.Herein,we find a boron nitride(BN)-immobilized Ni catalyst shows unprecedented coking resistance in dry reforming of methane via the incomplete decomposition of methane.Unlike the Ni-based catalysts supported by traditional metal oxides,BN-supported Ni accelerates the first C-H dissociation while inhibiting the breaking of the final C-H bond;hence,the suppression of the complete decomposition of methane thoroughly addresses the coking issue.This work reveals the fundamental reason for the coking resistance over BN-supported Ni catalysts is selective activation of the C-H bond,which can provide an inspiring idea for other applications.展开更多
基金the support from the National Key Research and Development Program of China(No.2023YFA1508500)the National Natural Science Foundation of China(No.22276120)。
文摘Chlorobenzene is a model molecule for researching harmful chlorinated volatile organic compounds.Designing the chemical adsorption site for complex molecules such as chlorobenzene is challenging without a large dataset and reasonable descriptors.Here,the adsorption of chlorobenzene on a phosphorylated CeO_(2)catalyst was analyzed using density functional theory calculations.Three different surface phosphate(H_(x)PO_(4))models were constructed and used to adsorb chlorobenzene.An orbital interaction with fully occupied antibonding is found in one of three physical adsorptions.Based on this,the surface sites of a tri-cluster(M_(3))located at the CeO_(2)surface have been suggested to activate chlorobenzene.Three different clusters have been tested,namely Fe_(3),Ru_(3),and B_(3).All these clusters can activate and twist chlorobenzene by donating electrons.Fe_(3)and Ru_(3)form bonds with weak covalent and strong ionic characters,while B3forms strong covalent bonds between boron and carbon.This work not only predicts a class of sites for chlorobenzene activation that may prevent polychlorinated by-products but also gives a template for catalyst rational design according to fundamental catalytic theory.
文摘The atomic structure of the active sites in Cu/CeO2 catalysts is intimately associated with the copper-ceria interaction. Both the shape of ceria and the loading of copper affect the chemical bonding of copper species on ceria surfaces and the electronic and geometric character of the relevant interfaces. Nanostructured ceria, including particles(polyhedra), rods, and cubes, provides anchoring sites for the copper species. The atomic arrangements and chemical properties of the(111),(110) and(100) facets, preferentially exposed depending on the shape of ceria, govern the copper-ceria interactions and in turn determine their catalytic properties. Also, the metal loading significantly influences the dispersion of copper species on ceria with a specific shape, forming copper layers, clusters, and nanoparticles. Lower copper contents result in copper monolayers and/or bilayers while higher copper loadings lead to multi-layered clusters and faceted particles. The active sites are usually generated via interactions between the copper atoms in the metal species and the oxygen vacancies on ceria, which is closely linked to the number and density of surface oxygen vacancies dominated by the shape of ceria.
基金the National Natural Science Foundation of China(No.22125604)Shanghai Rising-Star Program(No.22QA1403700)Chenguang Program supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission(No.22Z00354).
文摘The presence of alkali metals in exhaust gas from stationary resources causes a grand challenge for the practical application of selective catalytic reduction(SCR)of NO_(x) with NH_(3).Here,alkali-resistant NO_(x) reduction has been successfully implemented via tailoring the electron transfer over Fe and V species on FeVO_(4)/TiO_(2)catalysts.The strong interaction between Fe and V induced electron transfer from V to Fe and strengthened the adsorption and activation of NH_(3)and NO over active VO_(x) sites.In the presence of K_(2)O,the strong electron withdrawing effect of Fe offset the electron donating effect of K on the VO_(x) species,thus protecting the active species VO_(x) to maintain the NO_(x) reduction ability.The enhanced adsorption and activation of NH_(3) allowed SCR reaction to proceed via E-R mechanism even after K_(2)O poisoning.This work elucidated the electronic effects on the alkali metals resistance of traditional ferric vanadate SCR catalysts and provided a promising strategy to design SCR catalysts with superior alkali resistance.
基金financial support from the National Natural Science Foundation of China(grant nos.22006098 and 22125604)Shanghai Sailing Program(grant no.20YF1413300)+1 种基金J.D.thanks Dr.Lei Xie at Fudan University for fruitful discussions.The computational part is also supported by the JSPS KAKENHI(grant no.JP20K05217)the supercomputer at RCCS(grant no.22-IMS-C002),Okazaki,Japan.
文摘Metal oxides have been used as the supports for heterogeneous catalysis formany years,but they still suffer from coking in some high-temperature applications.The main reasons for coking are the uncontrollable dissociation of C-H and the overbalance between carbon deposition and removal.Herein,we find a boron nitride(BN)-immobilized Ni catalyst shows unprecedented coking resistance in dry reforming of methane via the incomplete decomposition of methane.Unlike the Ni-based catalysts supported by traditional metal oxides,BN-supported Ni accelerates the first C-H dissociation while inhibiting the breaking of the final C-H bond;hence,the suppression of the complete decomposition of methane thoroughly addresses the coking issue.This work reveals the fundamental reason for the coking resistance over BN-supported Ni catalysts is selective activation of the C-H bond,which can provide an inspiring idea for other applications.
