The neutral oxygen evolution reaction(OER)in lower OH^(−)-concentration environments suffers from sluggish reaction kinetics,presenting significant challenges for the design of efficient and low-cost electrocatalysts....The neutral oxygen evolution reaction(OER)in lower OH^(−)-concentration environments suffers from sluggish reaction kinetics,presenting significant challenges for the design of efficient and low-cost electrocatalysts.Effectively manipulating the local reaction environment could provide a promising solution.Here,we report a Brønsted base silicate(SiO_(3)^(2−))-modified NiFe(OH)_(x) catalyst.As a proton acceptor,Brønsted base SiO_(3)^(2−)accelerates the cleavage of OH-H bonds at Ni/Fe sites(^(*)H_(2)O→^(*)OH+H^(+)+e^(−)),thereby facilitating ^(*)OH accumulation and enhancing the local ^(*)OH-enriched reaction environment.With these advantages,the optimized NiFe(OH)^(x)-SiO_(3)^(2−)catalyst exhibits a low OER overpotential of 280 mV at 10 mA cm−2,a 150 mV reduction compared to the unmodified NiFe(OH)_(x) catalyst.Furthermore,the membrane electrode assembly electrolyzer using NiFe(OH)_(x)-SiO_(3)^(2−)||Pt/C achieves an energy conversion efficiency of 69.2%and a current density of 1.0 A cm^(−2) at 1.81 V,maintaining stable performance over 240 hours with a negligible degradation.The strategy of Brønsted base SiO_(3)^(2−)modification offers a promising and cost-effective approach for enhancing the efficiency of neutral water electrolysis.展开更多
基金supported by the National Natural Science Foundation of China(No.52204320 and 52034004)the National Key Research and Development Program of China(2023YFA1507903).
文摘The neutral oxygen evolution reaction(OER)in lower OH^(−)-concentration environments suffers from sluggish reaction kinetics,presenting significant challenges for the design of efficient and low-cost electrocatalysts.Effectively manipulating the local reaction environment could provide a promising solution.Here,we report a Brønsted base silicate(SiO_(3)^(2−))-modified NiFe(OH)_(x) catalyst.As a proton acceptor,Brønsted base SiO_(3)^(2−)accelerates the cleavage of OH-H bonds at Ni/Fe sites(^(*)H_(2)O→^(*)OH+H^(+)+e^(−)),thereby facilitating ^(*)OH accumulation and enhancing the local ^(*)OH-enriched reaction environment.With these advantages,the optimized NiFe(OH)^(x)-SiO_(3)^(2−)catalyst exhibits a low OER overpotential of 280 mV at 10 mA cm−2,a 150 mV reduction compared to the unmodified NiFe(OH)_(x) catalyst.Furthermore,the membrane electrode assembly electrolyzer using NiFe(OH)_(x)-SiO_(3)^(2−)||Pt/C achieves an energy conversion efficiency of 69.2%and a current density of 1.0 A cm^(−2) at 1.81 V,maintaining stable performance over 240 hours with a negligible degradation.The strategy of Brønsted base SiO_(3)^(2−)modification offers a promising and cost-effective approach for enhancing the efficiency of neutral water electrolysis.
