Tailoring the Ti coordination states in titanosilicate zeolites to simultaneously improve feedstock conversion and maximize the target product selectivity remains a challenge in the pursuit of high-performance catalys...Tailoring the Ti coordination states in titanosilicate zeolites to simultaneously improve feedstock conversion and maximize the target product selectivity remains a challenge in the pursuit of high-performance catalysts for selective oxidation reactions.Herein,we provide a facile strategy to synthesize hierarchical anatase-free TS-1(MFI-type)zeolites with tetrahedrally coordinated(TiO_(4))and octahedrally coordinated Ti species(TiO_(6)).The TiO_(4)species provide high epoxide selectivity,while the TiO_(6)species afford improved alkene conversion.This strategy is achieved by synergistically using an L-lysine-assisted approach and a two-step crystallization;the two-step crystallization approach prevents the formation of anatase TiO_(2),while L-lysine stabilizes the TiO_(6)species and ensures efficient incorporation of TiO_(6)into the anatase-free TS-1 zeolites.Compared with their conventional counterparts,which only contain TiO_(4)species,the as-prepared TS-1 zeolites(Si/Ti=36.9)result in a higher 1-hexene conversion(33%),higher TON value(153),and comparable epoxide selectivity(95%).This synthetic strategy provides avenues to tailor the amount and distribution of Ti species in titanosilicate zeolites to achieve high catalytic performances in various processes.展开更多
Feasible construction of cathode materials with highly dispersed active sites can extend the tri‐ple‐phase boundaries,and therefore leading to enhanced electrode kinetics for CO_(2) electrolysis in solid oxide elect...Feasible construction of cathode materials with highly dispersed active sites can extend the tri‐ple‐phase boundaries,and therefore leading to enhanced electrode kinetics for CO_(2) electrolysis in solid oxide electrolysis cell(SOEC).Herein,highly dispersed nickel species with low loading(1.0 wt%)were trapped within the La_(0.8)Sr_(0.2)FeO_(3)–δ‐Ce_(0.8)Sm_(0.2)O_(2)–δvia a facial mechanical milling ap‐proach,which demonstrated excellent CO_(2) electrolysis performance.The highly dispersed nickel species can significantly alter the electronic structures of the LSF‐SDC without affecting its porous network and facilitate oxygen vacancy formation,thus greatly promote the CO_(2) electrolysis perfor‐mance.The highest current density of 1.53 A·cm^(-2) could be achieved when operated under 800℃ at 1.6 V,which is about 91%higher than the LSF‐SDC counterpart.展开更多
文摘Tailoring the Ti coordination states in titanosilicate zeolites to simultaneously improve feedstock conversion and maximize the target product selectivity remains a challenge in the pursuit of high-performance catalysts for selective oxidation reactions.Herein,we provide a facile strategy to synthesize hierarchical anatase-free TS-1(MFI-type)zeolites with tetrahedrally coordinated(TiO_(4))and octahedrally coordinated Ti species(TiO_(6)).The TiO_(4)species provide high epoxide selectivity,while the TiO_(6)species afford improved alkene conversion.This strategy is achieved by synergistically using an L-lysine-assisted approach and a two-step crystallization;the two-step crystallization approach prevents the formation of anatase TiO_(2),while L-lysine stabilizes the TiO_(6)species and ensures efficient incorporation of TiO_(6)into the anatase-free TS-1 zeolites.Compared with their conventional counterparts,which only contain TiO_(4)species,the as-prepared TS-1 zeolites(Si/Ti=36.9)result in a higher 1-hexene conversion(33%),higher TON value(153),and comparable epoxide selectivity(95%).This synthetic strategy provides avenues to tailor the amount and distribution of Ti species in titanosilicate zeolites to achieve high catalytic performances in various processes.
文摘Feasible construction of cathode materials with highly dispersed active sites can extend the tri‐ple‐phase boundaries,and therefore leading to enhanced electrode kinetics for CO_(2) electrolysis in solid oxide electrolysis cell(SOEC).Herein,highly dispersed nickel species with low loading(1.0 wt%)were trapped within the La_(0.8)Sr_(0.2)FeO_(3)–δ‐Ce_(0.8)Sm_(0.2)O_(2)–δvia a facial mechanical milling ap‐proach,which demonstrated excellent CO_(2) electrolysis performance.The highly dispersed nickel species can significantly alter the electronic structures of the LSF‐SDC without affecting its porous network and facilitate oxygen vacancy formation,thus greatly promote the CO_(2) electrolysis perfor‐mance.The highest current density of 1.53 A·cm^(-2) could be achieved when operated under 800℃ at 1.6 V,which is about 91%higher than the LSF‐SDC counterpart.
