Understanding the origin of the catalytic activity for the development of efficient catalysts is critical yet challenging.Herein,we report a simple strategy for the synthesis of chromium nitride nanoparticles(CrNNPs)e...Understanding the origin of the catalytic activity for the development of efficient catalysts is critical yet challenging.Herein,we report a simple strategy for the synthesis of chromium nitride nanoparticles(CrNNPs)encapsulated into hollow chromium-nitrogen-carbon capsules(CrN@H-Cr-N_(x)-C).The CrN@H-Cr-N_(x)-C demonstrated excellent electrocatalytic activity for the oxygen reduction reaction(ORR)in acidic solutions.When applied as a cathode material in a proton-exchange membrane fuel cell(PEMFC),the CrN@H-Cr-N_(x)-C achieved outstanding initial performance,which is better than that of the PEMFC with H-Cr-N_(x)-C cathode material.The CrN@H-Cr-N_(x)-C cathode also showed good stability over 110 h of operation.These results demonstrated that the coexistence of atomically dispersed CrN_(x) sites and sufficient CrNNPs is essential for excellent PEMFC performances.Density functional theory(DFT)studies further corroborated that CrNNPs can boost the ORR activity of H-Cr-N_(x)-C.This finding opens a new avenue for the fabrication of low-cost,highly active,and durable ORR catalysts for PEMFC and other applications.展开更多
基金The authors gratefully acknowledge the support from the Robert A.Welch Foundation(B-0027)(S.M.).Support from North China Electric Power University(no.XM2009903)the National Science Foundation of China(grant no.22006036)are also acknowledged(H.Y.and X.W.).R.W.M.and J.T.W.acknowledge support from the U.S.National Science Foundation(no.DMR-1708617)Materials Research Collaborative Access Team(MRCAT)operations are supported by the Department of Energy(DOE)and the MRCAT member institutions.This research used resources of the Advanced Photon Source,a U.S.DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract no.DE-AC02-06CH11357.
文摘Understanding the origin of the catalytic activity for the development of efficient catalysts is critical yet challenging.Herein,we report a simple strategy for the synthesis of chromium nitride nanoparticles(CrNNPs)encapsulated into hollow chromium-nitrogen-carbon capsules(CrN@H-Cr-N_(x)-C).The CrN@H-Cr-N_(x)-C demonstrated excellent electrocatalytic activity for the oxygen reduction reaction(ORR)in acidic solutions.When applied as a cathode material in a proton-exchange membrane fuel cell(PEMFC),the CrN@H-Cr-N_(x)-C achieved outstanding initial performance,which is better than that of the PEMFC with H-Cr-N_(x)-C cathode material.The CrN@H-Cr-N_(x)-C cathode also showed good stability over 110 h of operation.These results demonstrated that the coexistence of atomically dispersed CrN_(x) sites and sufficient CrNNPs is essential for excellent PEMFC performances.Density functional theory(DFT)studies further corroborated that CrNNPs can boost the ORR activity of H-Cr-N_(x)-C.This finding opens a new avenue for the fabrication of low-cost,highly active,and durable ORR catalysts for PEMFC and other applications.
