Developing highly efficient and stable platinum-based electrocatalyst for oxygen reduction reaction(ORR) is critical to expediting commercialization of fuel cells.Herein,several PtCu alloy nanocatalysts supported on N...Developing highly efficient and stable platinum-based electrocatalyst for oxygen reduction reaction(ORR) is critical to expediting commercialization of fuel cells.Herein,several PtCu alloy nanocatalysts supported on N,P co-doped carbon(PtCu/NPC) were prepared by microbial-sorption and carbonization-reduction.Among them,PtCu/NPC-700 ℃ exhibits excellent catalytic performance for ORR with a mass activity of 0.895 A mg_(pt)^(-1)(@0.9 V) which is 8.29 folds of commercial Pt/C.Additionally,the ECSA and MA of PtCu/NPC-700℃ only decrease by 14.2% and 18.7% respectively,while Pt/C decreases by 35.2% and 52.8% after 10,000 cycles of ADT test.Moreover,the PtCu/NPC-700℃ catalyst emanates a maximum power density of 715 mW cm^(-2) and only 11.1% loss of maximum power density after 10,000 ADTs in single-cell test,indicating PtCu/NPC-700℃ also manifests higher activity and durability in actual single-cell operation than Pt/C.This research provides an easy and novel strategy for developing highly active and durable Pt-based alloy catalyst.展开更多
Zeolite-encapsulated Pt-based alloy catalysts exhibit exceptional activity and sintering resistance in propane dehydrogenation(PDH).However,their preparation generally relies on the ligand-protected hydrothermal synth...Zeolite-encapsulated Pt-based alloy catalysts exhibit exceptional activity and sintering resistance in propane dehydrogenation(PDH).However,their preparation generally relies on the ligand-protected hydrothermal synthesis method,which suffers from high cost,organic pollution,and low metal utilization,thereby limiting their large-scale preparation and application.Here,we developed a post-treatment strategy based on metal replacement reaction to form subnanometer PtCu alloy in Cu-exchanged zeolite.Copper cations(Cu^(2+) )were first introduced into ZSM-5(MFI)via ion exchange,followed by reduction to form Cu^(0)/Cu^(+) nanoparticles(CuO_(x))inside the zeolite.Subsequently,Pt^(2+) ions were incorporated to form PtCu alloy supported on CuO_(x) nanoparticles via a metal replacement reaction.The as-prepared PtCu5@MFI-K(Pt/Cu=1/5)achieved 49.7%propane conversion with>90%propylene selectivity alongside excellent regeneration stability.The forward rate constant(k_(f))of PtCu5@MFI-K at 550℃ reached 868 molC3H6 gPt^(−1) h^(−1) bar^(−1),which was higher than that of previously reported zeolite-encapsulated Pt-based catalysts.Significantly,Pt and Cu species could dynamically recombine to form PtCu alloy during the regeneration process,showing excellent sinterresistant ability of PtCu5@MFI-K.This work presents a facile,simple,and cost-effective strategy for preparing alloy@zeolite catalysts with tailored metal compositions for important catalytic reactions.展开更多
基金supported by funding from the National Natural Science Foundation of China (12074435 and 52001335)the Science and Technology Innovation Program of Hunan Province (2021RC4001)the Natural Science Foundation of Yunnan Province (202201AT070259)。
文摘Developing highly efficient and stable platinum-based electrocatalyst for oxygen reduction reaction(ORR) is critical to expediting commercialization of fuel cells.Herein,several PtCu alloy nanocatalysts supported on N,P co-doped carbon(PtCu/NPC) were prepared by microbial-sorption and carbonization-reduction.Among them,PtCu/NPC-700 ℃ exhibits excellent catalytic performance for ORR with a mass activity of 0.895 A mg_(pt)^(-1)(@0.9 V) which is 8.29 folds of commercial Pt/C.Additionally,the ECSA and MA of PtCu/NPC-700℃ only decrease by 14.2% and 18.7% respectively,while Pt/C decreases by 35.2% and 52.8% after 10,000 cycles of ADT test.Moreover,the PtCu/NPC-700℃ catalyst emanates a maximum power density of 715 mW cm^(-2) and only 11.1% loss of maximum power density after 10,000 ADTs in single-cell test,indicating PtCu/NPC-700℃ also manifests higher activity and durability in actual single-cell operation than Pt/C.This research provides an easy and novel strategy for developing highly active and durable Pt-based alloy catalyst.
基金the National Key Research and Development Program of China(grant no.2021YFA1501202)the National Natural Science Foundation of China(grant no.22288101)the“111 center”(grant no.B17020)for supporting this work.
文摘Zeolite-encapsulated Pt-based alloy catalysts exhibit exceptional activity and sintering resistance in propane dehydrogenation(PDH).However,their preparation generally relies on the ligand-protected hydrothermal synthesis method,which suffers from high cost,organic pollution,and low metal utilization,thereby limiting their large-scale preparation and application.Here,we developed a post-treatment strategy based on metal replacement reaction to form subnanometer PtCu alloy in Cu-exchanged zeolite.Copper cations(Cu^(2+) )were first introduced into ZSM-5(MFI)via ion exchange,followed by reduction to form Cu^(0)/Cu^(+) nanoparticles(CuO_(x))inside the zeolite.Subsequently,Pt^(2+) ions were incorporated to form PtCu alloy supported on CuO_(x) nanoparticles via a metal replacement reaction.The as-prepared PtCu5@MFI-K(Pt/Cu=1/5)achieved 49.7%propane conversion with>90%propylene selectivity alongside excellent regeneration stability.The forward rate constant(k_(f))of PtCu5@MFI-K at 550℃ reached 868 molC3H6 gPt^(−1) h^(−1) bar^(−1),which was higher than that of previously reported zeolite-encapsulated Pt-based catalysts.Significantly,Pt and Cu species could dynamically recombine to form PtCu alloy during the regeneration process,showing excellent sinterresistant ability of PtCu5@MFI-K.This work presents a facile,simple,and cost-effective strategy for preparing alloy@zeolite catalysts with tailored metal compositions for important catalytic reactions.
