The catalytic performance of light-derived CO_(2)reduction with H_(2)O is strongly dependent on the sepa-ration efficiency of photogenerated carriers.Herein,the direct Z-scheme catalysts(g-C_(3)N_(4)/3DOM-WO_(3))of gr...The catalytic performance of light-derived CO_(2)reduction with H_(2)O is strongly dependent on the sepa-ration efficiency of photogenerated carriers.Herein,the direct Z-scheme catalysts(g-C_(3)N_(4)/3DOM-WO_(3))of graphitic carbon nitride(g-C_(3)N_(4))nanosheets decorated three-dimensional ordered macroporous WO_(3)(3DOM-WO_(3))were successfully fabricated by using the in-situ colloidal crystal template method.The slow light effect of 3DOM-WO_(3)photonic crystals expands the absorption of visible light and improves the uti-lization of light energy.The Z-scheme structure of g-C_(3)N_(4)/3DOM-WO_(3)catalysts is able to upgrade the separation efficiency of photogenerated electron-hole pairs.The g-C_(3)N_(4)/3DOM-WO_(3)photocatalyst,whose formation rate of CO product is 48.7μmol g^(−1)h^(−1),exhibits the excellent catalytic activity for CO_(2)reduc-tion.The transfer pathway of stimulated electrons over the g-C_(3)N_(4)/3DOM-WO_(3)photocatalyst is proposed and discussed.The present approach provides unique insights into the rational development of high-performance photochemical systems for efficient CO_(2)reduction into valuable carbon-containing chemicals and energy fuels.展开更多
NH_(3)-SCR is an effective mean of NOxremoval in the non-electric industry, however, the high activation temperature and poor H_(2)O resistance of SCR catalysts posed a barrier to its application. In this work, a seri...NH_(3)-SCR is an effective mean of NOxremoval in the non-electric industry, however, the high activation temperature and poor H_(2)O resistance of SCR catalysts posed a barrier to its application. In this work, a series of three-dimensionally ordered macroporous(3DOM) catalysts were synthesized via a colloidal crystal template(CCT) method, and various characterizations were carried out to explore the physicochemical property of catalysts. The experiment results reveal that Ce_(0.2)Mn_(0.2)/3DOM-TiO_(2) catalyst presents the excellent low-temperature catalytic activity of nearly 100% at 100℃. Furthermore, the enhanced H_(2)O resistance is achieved, certified by the unaffected NO remove at 150℃ in the participation of 15 vol% H_(2)O. The characterizations results exhibit that the improved dispersion of the active component and enhanced redox ability are conducive to the low-temperature catalytic activity. N_(2) adsorption and desorption experiments indicate that catalyst with 3DOM support possesses a larger pore diameter and specific surface area, which may weaken the condensation of H_(2)O in the microporosity of catalysts and improved the H_(2)O resistance of the catalyst. In situ DRIFTS results manifest that Ce_(0.2)Mn_(0.2)/3DOM-TiO_(2) catalyst could not only absorb more NH_(3) and generate more surface-active sites, but inhibit the competitive adsorption between H_(2)O and SCR reactants.展开更多
The rapid recombination of photoinduced electron-hole pairs as well as the deficiency of high-energy carriers restricted the redox ability and products selectivity.Herein,the heterojunction of SnS_(2)-deco rated three...The rapid recombination of photoinduced electron-hole pairs as well as the deficiency of high-energy carriers restricted the redox ability and products selectivity.Herein,the heterojunction of SnS_(2)-deco rated three-dimensional ordered macropores(3DOM)-SrTiO_(3) catalysts were in-situ constructed to provide transmit channel for high-energy electron transmission.The suitable band edges of SnS_(2) and SrTiO_(3) contribute to the Z-scheme transfer of photogenerated carrier.The 3DOM structure of SrTiO_(3)-based catalyst possesses the slow light effect for enhancing light adsorption efficiency,and the surface alkalis strontium is benefit to the boosting adsorption for CO_(2).The in-situ introduced SnS_(2) decorated on the macroporous wall surface of 3DOM-SrTiO_(3) altered the primary product from CO to CH4.The Z-scheme electron transfer from SnS_(2) combining with the holes in SrTiO_(3) occurred under full spectrum photoexcitation,which improved the excitation and utilization of photogene rated electrons for C02 multi-electrons reduction.As a result,(SnS_(2))3/3 DOM-SrTiO_(3) catalyst exhibits higher activity for photocatalytic CO_(2) reduction to CH4 compared with single SnS_(2) or 3 DOM-SrTiO_(3),i.e.,its yield and selectivity of CH4 are 12.5μmol g^(-1) h^(-1) and 74.9%,re spectively.The present work proposed the theoretical foundation of Z-scheme heterojunction construction for enhancing photocatalytic activity and selectivity for CO_(2) conversion.展开更多
A series of heteropoly acid (HPA) based Al2O3 catalysts with three-dimensional ordered (3DOM) structure were synthesized by colloidal crystal template method.Interconnected macropores (250 nm) could be clearly observe...A series of heteropoly acid (HPA) based Al2O3 catalysts with three-dimensional ordered (3DOM) structure were synthesized by colloidal crystal template method.Interconnected macropores (250 nm) could be clearly observed by scanning electron microscope (SEM) and transmission electron microscope (TEM).Mesopores could be detected by N2 adsorption-desorption isotherms which further confirmed the 3DOM structural characteristics of catalyst.Moreover,Keggin-type HPW was highly dispersed in the Al2O3 framework,which suggested by powder X-ray diffraction (XRD) and Fourier transform infrared spectra (FT-IR) results.The oxidation desulfurization (ODS) performance of 3DOM H3PW12O40/Al2O3 of refractory sulphur compounds was evaluated in the presence of hydrogen peroxide.It oxidized 98.5% of dibenzothiophene (DBT) into corresponding sulfone within 3 h,which exhibited superior ODS performance than corresponding mesoporous and microporous H3PW12O40/Al2O3 catalyst.The enhancement of ODS efficiency is related to the improvement of mass transfer of DBT in the pore channel resulting from the interconnected 3DOM structure.Furthermore,the as-prepared catalyst still demonstrates outstanding cycle performance after 6 runs,which could be easily recovered from the model fuel.展开更多
基金supported by the National Natural Science Foundation of China (No.21972166)Beijing Natural Science Foundation (No.2202045)National Key Research and Development Program of China (No.2019YFC1907600)。
文摘The catalytic performance of light-derived CO_(2)reduction with H_(2)O is strongly dependent on the sepa-ration efficiency of photogenerated carriers.Herein,the direct Z-scheme catalysts(g-C_(3)N_(4)/3DOM-WO_(3))of graphitic carbon nitride(g-C_(3)N_(4))nanosheets decorated three-dimensional ordered macroporous WO_(3)(3DOM-WO_(3))were successfully fabricated by using the in-situ colloidal crystal template method.The slow light effect of 3DOM-WO_(3)photonic crystals expands the absorption of visible light and improves the uti-lization of light energy.The Z-scheme structure of g-C_(3)N_(4)/3DOM-WO_(3)catalysts is able to upgrade the separation efficiency of photogenerated electron-hole pairs.The g-C_(3)N_(4)/3DOM-WO_(3)photocatalyst,whose formation rate of CO product is 48.7μmol g^(−1)h^(−1),exhibits the excellent catalytic activity for CO_(2)reduc-tion.The transfer pathway of stimulated electrons over the g-C_(3)N_(4)/3DOM-WO_(3)photocatalyst is proposed and discussed.The present approach provides unique insights into the rational development of high-performance photochemical systems for efficient CO_(2)reduction into valuable carbon-containing chemicals and energy fuels.
基金Project supported by National Key Research and Development Program of China(2021YFB3500601)。
文摘NH_(3)-SCR is an effective mean of NOxremoval in the non-electric industry, however, the high activation temperature and poor H_(2)O resistance of SCR catalysts posed a barrier to its application. In this work, a series of three-dimensionally ordered macroporous(3DOM) catalysts were synthesized via a colloidal crystal template(CCT) method, and various characterizations were carried out to explore the physicochemical property of catalysts. The experiment results reveal that Ce_(0.2)Mn_(0.2)/3DOM-TiO_(2) catalyst presents the excellent low-temperature catalytic activity of nearly 100% at 100℃. Furthermore, the enhanced H_(2)O resistance is achieved, certified by the unaffected NO remove at 150℃ in the participation of 15 vol% H_(2)O. The characterizations results exhibit that the improved dispersion of the active component and enhanced redox ability are conducive to the low-temperature catalytic activity. N_(2) adsorption and desorption experiments indicate that catalyst with 3DOM support possesses a larger pore diameter and specific surface area, which may weaken the condensation of H_(2)O in the microporosity of catalysts and improved the H_(2)O resistance of the catalyst. In situ DRIFTS results manifest that Ce_(0.2)Mn_(0.2)/3DOM-TiO_(2) catalyst could not only absorb more NH_(3) and generate more surface-active sites, but inhibit the competitive adsorption between H_(2)O and SCR reactants.
基金the National Natural Science Foundation of China(Nos.21673142,21972166)Beijing Natural Science Foundation(No.2202045)+1 种基金Petro China Innovation Foundation(No.2018D-5007-0505)Science Foundation of China University of Petroleum,Beijing(Nos.242017QNXZ02,2462018BJC005)。
文摘The rapid recombination of photoinduced electron-hole pairs as well as the deficiency of high-energy carriers restricted the redox ability and products selectivity.Herein,the heterojunction of SnS_(2)-deco rated three-dimensional ordered macropores(3DOM)-SrTiO_(3) catalysts were in-situ constructed to provide transmit channel for high-energy electron transmission.The suitable band edges of SnS_(2) and SrTiO_(3) contribute to the Z-scheme transfer of photogenerated carrier.The 3DOM structure of SrTiO_(3)-based catalyst possesses the slow light effect for enhancing light adsorption efficiency,and the surface alkalis strontium is benefit to the boosting adsorption for CO_(2).The in-situ introduced SnS_(2) decorated on the macroporous wall surface of 3DOM-SrTiO_(3) altered the primary product from CO to CH4.The Z-scheme electron transfer from SnS_(2) combining with the holes in SrTiO_(3) occurred under full spectrum photoexcitation,which improved the excitation and utilization of photogene rated electrons for C02 multi-electrons reduction.As a result,(SnS_(2))3/3 DOM-SrTiO_(3) catalyst exhibits higher activity for photocatalytic CO_(2) reduction to CH4 compared with single SnS_(2) or 3 DOM-SrTiO_(3),i.e.,its yield and selectivity of CH4 are 12.5μmol g^(-1) h^(-1) and 74.9%,re spectively.The present work proposed the theoretical foundation of Z-scheme heterojunction construction for enhancing photocatalytic activity and selectivity for CO_(2) conversion.
基金Funded by the National Natural Science Foundation of China(No.21476177)。
文摘A series of heteropoly acid (HPA) based Al2O3 catalysts with three-dimensional ordered (3DOM) structure were synthesized by colloidal crystal template method.Interconnected macropores (250 nm) could be clearly observed by scanning electron microscope (SEM) and transmission electron microscope (TEM).Mesopores could be detected by N2 adsorption-desorption isotherms which further confirmed the 3DOM structural characteristics of catalyst.Moreover,Keggin-type HPW was highly dispersed in the Al2O3 framework,which suggested by powder X-ray diffraction (XRD) and Fourier transform infrared spectra (FT-IR) results.The oxidation desulfurization (ODS) performance of 3DOM H3PW12O40/Al2O3 of refractory sulphur compounds was evaluated in the presence of hydrogen peroxide.It oxidized 98.5% of dibenzothiophene (DBT) into corresponding sulfone within 3 h,which exhibited superior ODS performance than corresponding mesoporous and microporous H3PW12O40/Al2O3 catalyst.The enhancement of ODS efficiency is related to the improvement of mass transfer of DBT in the pore channel resulting from the interconnected 3DOM structure.Furthermore,the as-prepared catalyst still demonstrates outstanding cycle performance after 6 runs,which could be easily recovered from the model fuel.
