Although Pt Ni catalyst possesses good oxygen reduction activity, its poor stability is the main obstacle for the commercialization of proton exchange membrane fuel cells(PEMFCs). In this work, we introduce the acid-r...Although Pt Ni catalyst possesses good oxygen reduction activity, its poor stability is the main obstacle for the commercialization of proton exchange membrane fuel cells(PEMFCs). In this work, we introduce the acid-resistant refractory Mo to enhance the structure stability and modify the electronic structure of Pt in the prepared PtNi catalyst, improving the catalytic activity for oxygen reduction reaction(ORR). In addition, near-surface Pt content in the nanoparticle is also optimized to balance the ORR activity and stability. The electrochemical results show that the alloy formed by Mo and Pt Ni is obviously more stable than the PtNi alloy alone, because the acid-resistant Mo and its oxides effectively prevent the dissolution of Pt. Especially, the Pt3 Ni3 MoN/C exhibits the optimal ORR catalytic performance in O2-saturated 0.1 mol L^(-1) HClO4 aqueous solutions, with mass activity(MA) of 900 m A mg^(-1) Pt at 0.90 V vs. RHE, which is 3.75 times enhancement compared with the commercial Pt/C(240 mA mg^(-1) Pt). After 30 k accelerated durability tests, its MA(690 m A mg^(-1) Pt) is still 2.88 times higher than the pristine Pt/C. This study thus provides a valuable method to design stable ORR catalysts with high efficiency and has great significance for the commercialization of PEMFCs.展开更多
Tuning strong metal-support interaction between Pt-based alloys and metal oxides is an effective strategy for modulating the performance of oxygen reduction reaction(ORR).Herein,Pt_(3)Ni alloy anchored on WO_(x) with ...Tuning strong metal-support interaction between Pt-based alloys and metal oxides is an effective strategy for modulating the performance of oxygen reduction reaction(ORR).Herein,Pt_(3)Ni alloy anchored on WO_(x) with different content of oxygen vacancies is synthesized,and the effect of unsaturated WO_(x) on ORR activity/stability is revealed.Electrochemical results indicate that ORR activity is positively correlated with oxygen vacancy concentration,while durability presents the opposite trend.Density functional theory(DFT)calculation results suggest that controlling the content of oxygen vacancies can usefully adjust the charge redistribution between Pt_(3)Ni and WO_(x),which can optimize the adsorption/activation of reactants,thus obtaining good ORR activity.This study uncovers the effect of unsaturated WO_(x) on ORR performance for Pt-based alloys and provides a promising strategy to design efficient and stable ORR catalysts.展开更多
基金supported by the National Natural Science Foundation of China (21872040)the Natural Science Foundation of Guangxi (2016GXNSFCB380002)+1 种基金the Hundred Talents Program of Guangxi Universitiesthe Excellence Scholars and Innovation Team of Guangxi Universities。
文摘Although Pt Ni catalyst possesses good oxygen reduction activity, its poor stability is the main obstacle for the commercialization of proton exchange membrane fuel cells(PEMFCs). In this work, we introduce the acid-resistant refractory Mo to enhance the structure stability and modify the electronic structure of Pt in the prepared PtNi catalyst, improving the catalytic activity for oxygen reduction reaction(ORR). In addition, near-surface Pt content in the nanoparticle is also optimized to balance the ORR activity and stability. The electrochemical results show that the alloy formed by Mo and Pt Ni is obviously more stable than the PtNi alloy alone, because the acid-resistant Mo and its oxides effectively prevent the dissolution of Pt. Especially, the Pt3 Ni3 MoN/C exhibits the optimal ORR catalytic performance in O2-saturated 0.1 mol L^(-1) HClO4 aqueous solutions, with mass activity(MA) of 900 m A mg^(-1) Pt at 0.90 V vs. RHE, which is 3.75 times enhancement compared with the commercial Pt/C(240 mA mg^(-1) Pt). After 30 k accelerated durability tests, its MA(690 m A mg^(-1) Pt) is still 2.88 times higher than the pristine Pt/C. This study thus provides a valuable method to design stable ORR catalysts with high efficiency and has great significance for the commercialization of PEMFCs.
基金supported by the National Natural Science Foundation of China(22162004,21872040)the Natural Science Foundation of Guangxi Province(2022JJD120011)the Opening Project of Guangxi Key Laboratory of Information Materials(211025-K).
文摘Tuning strong metal-support interaction between Pt-based alloys and metal oxides is an effective strategy for modulating the performance of oxygen reduction reaction(ORR).Herein,Pt_(3)Ni alloy anchored on WO_(x) with different content of oxygen vacancies is synthesized,and the effect of unsaturated WO_(x) on ORR activity/stability is revealed.Electrochemical results indicate that ORR activity is positively correlated with oxygen vacancy concentration,while durability presents the opposite trend.Density functional theory(DFT)calculation results suggest that controlling the content of oxygen vacancies can usefully adjust the charge redistribution between Pt_(3)Ni and WO_(x),which can optimize the adsorption/activation of reactants,thus obtaining good ORR activity.This study uncovers the effect of unsaturated WO_(x) on ORR performance for Pt-based alloys and provides a promising strategy to design efficient and stable ORR catalysts.
