The stress corrosion cracking( SCC) behavior of PH13-8Mo precipitation hardening stainless steel( PHSS) in neutral NaCl solutions was investigated through slow-strain-rate tensile( SSRT) test at various applied ...The stress corrosion cracking( SCC) behavior of PH13-8Mo precipitation hardening stainless steel( PHSS) in neutral NaCl solutions was investigated through slow-strain-rate tensile( SSRT) test at various applied potentials. Fracture morphology,elongation ratio,and percentage reduction of area were measured to evaluate the SCC susceptibility. A critical concentration of 1. 0 mol / L neutral NaCl existed for SCC of PH13-8Mo steel. Significant SCC emerged when the applied potential was more negative than -0. 15 VSCE,and the SCC behavior was controlled by an anodic dissolution( AD) process.When the applied potential was lower than -0. 55 VSCE,an obvious hydrogen-fracture morphology was observed,which indicated that the SCC behavior was controlled by hydrogen-induced cracking( HIC).Between -0. 15 and -0. 35 VSCE,the applied potential exceeded the equilibrium hydrogen evolution potential in neutral NaCl solutions and the crack tips were of electrochemical origin in the anodic region; thus,the SCC process was dominated by the AD mechanism.展开更多
High efficiency and low-cost catalyst-driven electrocatalytic CO_(2)reduction to CO production are of great significance for energy storage and development.The severe competitive hydrogen evolution reaction occurs at ...High efficiency and low-cost catalyst-driven electrocatalytic CO_(2)reduction to CO production are of great significance for energy storage and development.The severe competitive hydrogen evolution reaction occurs at large negative potential window limits the achievement of the target product from CO_(2)at high efficiency.Here,we successfully prepared Cu_(x)/CdcO_(3)composite catalyst rich in interfaces,in which achieved high CO Faraday eficiency exceeded 90%in a wide potential window of 700 mV and highest value up to 97.9%at-0.90V vs.RHE.The excellent performance can be ascribed to the positive contribution of Cu_(x)/CdcO_(3),which maintains a suitable high local pH value during electrochemical reduction,thus inhibiting the competitive hydrogen evolution reaction.Moreover,the compact structure between Cu and CdCO_(3)ensures fast electron transfer both inside catalysts and interface,thus speeding up the reaction kinetics of CO_(2)to CO conversion.Theoretically calculations further prove that the combination of Cu and CdcO_(3)provides the well-defined electronic structure for intermediates adsorption,significantly reducing the reaction barrier for the formation of co.This work provides new insights into the design of eficient electrochemical CO_(2)reduction catalysts for inhibiting hydrogen evolution by adjusting the local pH effect.展开更多
基金supported by the National Natural Science Foundation of China(No.51171023)the Fundamental Research Funds for the Central Universities(No.FRF-TP-14-011C1)+1 种基金National Basic Research Program of China(973 Program )(No.2014CB643300 )the Beijing Municipal Commission of Education
文摘The stress corrosion cracking( SCC) behavior of PH13-8Mo precipitation hardening stainless steel( PHSS) in neutral NaCl solutions was investigated through slow-strain-rate tensile( SSRT) test at various applied potentials. Fracture morphology,elongation ratio,and percentage reduction of area were measured to evaluate the SCC susceptibility. A critical concentration of 1. 0 mol / L neutral NaCl existed for SCC of PH13-8Mo steel. Significant SCC emerged when the applied potential was more negative than -0. 15 VSCE,and the SCC behavior was controlled by an anodic dissolution( AD) process.When the applied potential was lower than -0. 55 VSCE,an obvious hydrogen-fracture morphology was observed,which indicated that the SCC behavior was controlled by hydrogen-induced cracking( HIC).Between -0. 15 and -0. 35 VSCE,the applied potential exceeded the equilibrium hydrogen evolution potential in neutral NaCl solutions and the crack tips were of electrochemical origin in the anodic region; thus,the SCC process was dominated by the AD mechanism.
基金supported by the National Natural Science Foundation of China(Nos.22225808,22075111)Sino-German Cooperation Group Project(No.GZ1579)Jiangsu Province Innovation Support Program International Science and Technology Cooperation Project(No.BZ2022045).
文摘High efficiency and low-cost catalyst-driven electrocatalytic CO_(2)reduction to CO production are of great significance for energy storage and development.The severe competitive hydrogen evolution reaction occurs at large negative potential window limits the achievement of the target product from CO_(2)at high efficiency.Here,we successfully prepared Cu_(x)/CdcO_(3)composite catalyst rich in interfaces,in which achieved high CO Faraday eficiency exceeded 90%in a wide potential window of 700 mV and highest value up to 97.9%at-0.90V vs.RHE.The excellent performance can be ascribed to the positive contribution of Cu_(x)/CdcO_(3),which maintains a suitable high local pH value during electrochemical reduction,thus inhibiting the competitive hydrogen evolution reaction.Moreover,the compact structure between Cu and CdCO_(3)ensures fast electron transfer both inside catalysts and interface,thus speeding up the reaction kinetics of CO_(2)to CO conversion.Theoretically calculations further prove that the combination of Cu and CdcO_(3)provides the well-defined electronic structure for intermediates adsorption,significantly reducing the reaction barrier for the formation of co.This work provides new insights into the design of eficient electrochemical CO_(2)reduction catalysts for inhibiting hydrogen evolution by adjusting the local pH effect.