Formaldehyde（HCHO）is carcinogenic and teratogenic,and is therefore a serious danger to human health.It also adversely affects air quality.Catalytic oxidation is an efficient technique for removing HCHO.The developme...Formaldehyde（HCHO）is carcinogenic and teratogenic,and is therefore a serious danger to human health.It also adversely affects air quality.Catalytic oxidation is an efficient technique for removing HCHO.The development of highly efficient and stable catalysts that can completely convert HCHO at low temperatures,even room temperature,is important.Supported Pt and Pd catalysts can completely convert HCHO at room temperature,but their industrial applications are limited because they are expensive.The catalytic activities in HCHO oxidation of transition-metal oxide catalysts such as manganese and cobalt oxides with unusual morphologies are better than those of traditional MnO2,Co3O4,or other metal oxides.This is attributed to their specific structures,high specific surface areas,and other factors such as active phase,reducibility,and amount of surface active oxygens.Such catalysts with various morphologies have great potential and can also be used as catalyst supports.The loading of relatively cheap Ag or Au on transition-metal oxides with special morphologies potentially improves the catalytic activity in HCHO removal at room temperature.The preparation and development of new nanocatalysts with various morphologies and structures is important for HCHO removal.In this paper,research progress on precious-metal and transition-metal oxide catalyst systems for HCHO oxidation is reviewed; topics such as oxidation properties,structure–activity relationships,and factors influencing the catalytic activity and reaction mechanism are discussed.Future prospects and directions for the development of such catalysts are also covered.展开更多
Most of volatile organic compounds （VOCs） are harmful to the atmosphere and human health. Cata‐lytic combustion is an effective way to eliminate VOCs. The key issue is the availability of high per‐formance catalys...Most of volatile organic compounds （VOCs） are harmful to the atmosphere and human health. Cata‐lytic combustion is an effective way to eliminate VOCs. The key issue is the availability of high per‐formance catalysts. Many catalysts including transition metal oxides, mixed metal oxides, and sup‐ported noble metals have been developed. Among these catalysts, the porous ones attract much attention. In this review, we focus on recent advances in the synthesis of ordered mesoporous and macroporous transition metal oxides, perovskites, and supported noble metal catalysts and their catalytic oxidation of VOCs. The porous catalysts outperformed their bulk counterparts. This excel‐lent catalytic performance was due to their high surface areas, high concentration of adsorbed oxy‐gen species, low temperature reducibility, strong interaction between noble metal and support and highly dispersed noble metal nanoparticles and unique porous structures. Catalytic oxidation of carbon monoxide over typical catalysts was also discussed. We made conclusive remarks and pro‐posed future work for the removal of VOCs.展开更多
A new scheme for the preparation of highly dispersed precious metal catalysts is proposed in this work. Samples of LaCol-xPtxO3/SiO2 （x = 0.03, 0.05, 0.07, 0.09, and 0.10） were prepared through a simple method of ci...A new scheme for the preparation of highly dispersed precious metal catalysts is proposed in this work. Samples of LaCol-xPtxO3/SiO2 （x = 0.03, 0.05, 0.07, 0.09, and 0.10） were prepared through a simple method of citrate acid complexa-tion combined with impregnation. In a nanocrystallite of LaCOl-xPtxO3, ions of lanthanum, cobalt, and platinum are evenly mixed at the atomic level and confined within the nanocrystallite. In the reduction process, platinum ions were reduced and migrated onto the surface of the nanocrystallite, and the platinum should be highly dispersed owing to the even mixing of the platinum ions in the precursor. When x = 0.05 or lower, the highest dispersion of Pt could be achieved. The highly dispersed Pt is stable, because of the strong interaction between Pt atoms and the support. The catalysts were characterized by BET surface area, temperature-programmed reduction, X-ray diffraction, transmission electron microscopy, CO temperature-programmed desorption, and turnover frequency. Compared with general precious metal Pt catalysts, the LaCo0.95Pt0.05O3/ SiO2 catalyst exhibited better activity for CO oxidation, and it maintained stability at a high temperature of 400 ℃ for 250 h with complete CO conversion.展开更多
The design and synthesis of highly active non-noble metal oxide catalysts, such as transition- and rare-earth-metal oxides, have attracted significant attention because of their high efficiency and low cost and the re...The design and synthesis of highly active non-noble metal oxide catalysts, such as transition- and rare-earth-metal oxides, have attracted significant attention because of their high efficiency and low cost and the resultant potential applications for the degradation of volatile organic compounds(VOCs). The structure-activity relationships have been well-studied and used to facilitate design of the structure and composition of highly active catalysts. Recently, non-noble metal oxides with porous structures have been used as catalysts for deep oxidation of VOCs, such as aromatic hydrocarbons, aliphatic compounds, aldehydes, and alcohols, with comparable activities to their noble metal counterparts. This review summarizes the growing literature regarding the use of porous metal oxides for the catalytic removal of VOCs, with emphasis on design of the composition and structure and typical synthetic technologies.展开更多
基金supported by the National Natural Science Foundation of China(21325731,51478241,21221004)~~
文摘Formaldehyde（HCHO）is carcinogenic and teratogenic,and is therefore a serious danger to human health.It also adversely affects air quality.Catalytic oxidation is an efficient technique for removing HCHO.The development of highly efficient and stable catalysts that can completely convert HCHO at low temperatures,even room temperature,is important.Supported Pt and Pd catalysts can completely convert HCHO at room temperature,but their industrial applications are limited because they are expensive.The catalytic activities in HCHO oxidation of transition-metal oxide catalysts such as manganese and cobalt oxides with unusual morphologies are better than those of traditional MnO2,Co3O4,or other metal oxides.This is attributed to their specific structures,high specific surface areas,and other factors such as active phase,reducibility,and amount of surface active oxygens.Such catalysts with various morphologies have great potential and can also be used as catalyst supports.The loading of relatively cheap Ag or Au on transition-metal oxides with special morphologies potentially improves the catalytic activity in HCHO removal at room temperature.The preparation and development of new nanocatalysts with various morphologies and structures is important for HCHO removal.In this paper,research progress on precious-metal and transition-metal oxide catalyst systems for HCHO oxidation is reviewed; topics such as oxidation properties,structure–activity relationships,and factors influencing the catalytic activity and reaction mechanism are discussed.Future prospects and directions for the development of such catalysts are also covered.
基金supported by the National High Technology Research and Development Program (863 Program,2015AA034603)the National Natural Science Foundation of China (21377008,201077007,20973017)+1 种基金Foundation on the Creative Research Team Construction Promotion Project of Beijing Municipal InstitutionsScientific Research Base Construction-Science and Technology Creation Platform National Materials Research Base Construction~~
文摘Most of volatile organic compounds （VOCs） are harmful to the atmosphere and human health. Cata‐lytic combustion is an effective way to eliminate VOCs. The key issue is the availability of high per‐formance catalysts. Many catalysts including transition metal oxides, mixed metal oxides, and sup‐ported noble metals have been developed. Among these catalysts, the porous ones attract much attention. In this review, we focus on recent advances in the synthesis of ordered mesoporous and macroporous transition metal oxides, perovskites, and supported noble metal catalysts and their catalytic oxidation of VOCs. The porous catalysts outperformed their bulk counterparts. This excel‐lent catalytic performance was due to their high surface areas, high concentration of adsorbed oxy‐gen species, low temperature reducibility, strong interaction between noble metal and support and highly dispersed noble metal nanoparticles and unique porous structures. Catalytic oxidation of carbon monoxide over typical catalysts was also discussed. We made conclusive remarks and pro‐posed future work for the removal of VOCs.
基金supported by the National Natural Science Foundation of China(Nos.21576192,21776214)
文摘A new scheme for the preparation of highly dispersed precious metal catalysts is proposed in this work. Samples of LaCol-xPtxO3/SiO2 （x = 0.03, 0.05, 0.07, 0.09, and 0.10） were prepared through a simple method of citrate acid complexa-tion combined with impregnation. In a nanocrystallite of LaCOl-xPtxO3, ions of lanthanum, cobalt, and platinum are evenly mixed at the atomic level and confined within the nanocrystallite. In the reduction process, platinum ions were reduced and migrated onto the surface of the nanocrystallite, and the platinum should be highly dispersed owing to the even mixing of the platinum ions in the precursor. When x = 0.05 or lower, the highest dispersion of Pt could be achieved. The highly dispersed Pt is stable, because of the strong interaction between Pt atoms and the support. The catalysts were characterized by BET surface area, temperature-programmed reduction, X-ray diffraction, transmission electron microscopy, CO temperature-programmed desorption, and turnover frequency. Compared with general precious metal Pt catalysts, the LaCo0.95Pt0.05O3/ SiO2 catalyst exhibited better activity for CO oxidation, and it maintained stability at a high temperature of 400 ℃ for 250 h with complete CO conversion.
基金supported by the National High Technology Research and Development Program of China(2012AA062702)the strategic project of the Chinese Academy of Sciences(XDB05050000)
文摘The design and synthesis of highly active non-noble metal oxide catalysts, such as transition- and rare-earth-metal oxides, have attracted significant attention because of their high efficiency and low cost and the resultant potential applications for the degradation of volatile organic compounds(VOCs). The structure-activity relationships have been well-studied and used to facilitate design of the structure and composition of highly active catalysts. Recently, non-noble metal oxides with porous structures have been used as catalysts for deep oxidation of VOCs, such as aromatic hydrocarbons, aliphatic compounds, aldehydes, and alcohols, with comparable activities to their noble metal counterparts. This review summarizes the growing literature regarding the use of porous metal oxides for the catalytic removal of VOCs, with emphasis on design of the composition and structure and typical synthetic technologies.
