Fe,N,S-doped porous carbon as oxygen reduction reaction catalyst in acidic medium with high activity and durability synthesized using CaCl_2 as template

Proton exchange membrane fuel cells suffer from the sluggish kinetics of the oxygen reduction reaction(ORR)and the high cost of Pt catalysts.In the present work,a high‐performance ORR catalystbased on Fe,N,S‐doped porous carbon(FeNS‐PC)was synthesized using melamine formaldehyderesin as C and N precursors,Fe(SCN)3as Fe and S precursors,and CaCl2as a template via a two‐stepheat treatment without a harsh template removal step.The results show that the catalyst treated at900℃(FeNS‐PC‐900)had a high surface area of775m2/g,a high mass activity of10.2A/g in anacidic medium,and excellent durability;the half‐wave potential decreased by only20mV after10000potential cycles.The FeNS‐PC‐900catalyst was used as the cathode in a proton exchangemembrane fuel cell and delivered a peak power density of0.49W/cm2.FeNS‐PC‐900therefore hasgood potential for use in practical applications.

Highly dispersed few-layer MoS_2 nanosheets on S, N co-doped carbon for electrocatalytic H_2 production

Ultrathin small MoS2nanosheets exhibit a higher electrocatalytic activity for the hydrogen evolution reaction.However,strong interactions between MoS2layers may result in aggregation;together with the low conductivity of MoS2,this may lower its electrocatalytic activity.In this paper we present a method that we developed to directly produce solid S,N co‐doped carbon(SNC)with a graphite structure and multiple surface groups through a hydrothermal route.When Na2MoO4was added to the reaction,polymolybdate could be anchored into the carbon materials via a chemical interaction that helps polymolybdate disperse uniformly into the SNC.After a high temperature treatment,polymolybdate transformed into MoS2at800°C for6h in a N2atmosphere at a heating rate of5°C/min,owing to S2?being released from the SNC during the treatment(denoted as MoS2/SNC‐800‐6h).The SNC effectively prevents MoS2from aggregating into large particles,and we successfully prepared highly dispersed MoS2in the SNC matrix.Electrochemical characterizations indicate that MoS2/SNC‐900‐12h exhibits a low onset potential of115mV and a low overpotential of237mV at a current density of10mA/cm2.Furthermore,MoS2/SNC‐900‐12h also had an excellent stability with only^2.6%decay at a current density of10mA/cm2after5000test cycles.