P调控Pd的电子结构实现高效电解水析氢反应的性能分析  

Evaluation of Palladium Phosphide as Efficient Electrocatalyst for Hydrogen Evolution Reaction

作　　者：马荣鹏 杨小龙 王显[1,2] 葛君杰 刘长鹏[1,2] 邢巍[1,2] MA Rong-Peng;YANG Xiao-Long;WANG Xian;GE Jun-Jie;LIU Chang-Peng;XING Wei(Chinese Academy of Sciences,Changchun 130022,China;School of Applied Chemical Engineering,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学院长春应用化学研究所电分析化学国家重点实验室,长春130022 [2]中国科学技术大学应用化学与工程学院,合肥230026

出　　处：《分析化学》2021年第12期2032-2038,I0011-I0018,共15页Chinese Journal of Analytical Chemistry

基　　金：国家重点研发计划项目(No.2018YFB1502400);吉林省科技发展计划项目(Nos.20190201300JC,20180101030JC)资助。

摘　　要：电解水制氢具有高效环保、制备的氢气纯度高等优点。氢析出反应作为电解水的半反应之一,需要高效、低成本的电催化剂。钯基催化剂作为氢析出反应电催化剂之一,在电催化析氢反应(HER)中通常表现出低活性,主要原因是H与Pd形成的强的Pd—H键使得吸附H原子(H ad)的电化学脱附速度很慢,阻碍析氢反应的发生。本研究设计并合成了均一分散的磷化钯纳米颗粒(Pd_(3)P)嵌入在氮磷共掺杂碳材料表面(Pd_(3)P/NPC)的高效催化剂。当电流密度为10 mA/cm^(2)时,Pd_(3)P/NPC呈现11 mV的过电势,优于商业Pd/C和Pt/C,并且具有高稳定性。在过电势20 mV时,此催化剂的翻转频率(5.95 H_(2)/s)高于商业Pt/C和Pd/C催化剂。实验结果表明,P原子进入Pd纳米晶体会形成Pd—P键,改变Pd(0)和Pd含量,使得Pd的电子结构重构,促进H原子的脱附;同时P的引入增加了活性位点,提高了本征活性。Hydrogen production by water electrolysis has the advantages such as high efficiency and green development,and higher hydrogen purity.The development of efficient electrocatalysts for hydrogen evolution reaction(HER)must be based on the minimal overpotential to trigger proton reduction and fast kinetics.Palladium-based catalysts are used as one of the electrocatalysts for HER.However,they typically exhibit low activity in electrocatalytic hydrogen evolution reaction as too strong Pd—H bonding makes the electronic desorption of H adatoms(Had)hardly occur.Based on this,a highly efficient catalyst with uniformly dispersed palladium phosphide nanoparticles(Pd_(3)P NP)embedded in a nitrogen-phosphorus co-doped carbon material(Pd_(3)P/NPC)was designed and synthesized in this work.The Pd_(3)P/NPC presented a small overpotential of 11 mV to delivering 10 mA/cm^(2),and a robust stability,which was much better than Pd/C,other reported Pd-based catalysts,and even Pt/C.Moreover,the Pd_(3)P/NPC electrocatalyst exhibited high turnover frequencies at 20 mV(5.95 H_(2)/s).It was higher than that of commercial Pt/C and Pd/C catalysts.Experiments evidence revealed that the introduction of P atoms into the Pd nanocrystals formed a Pd—P bond,which restructured the electronic structure of Pd and changed the content of Pd(0)and Pd(+2),promoting the desorption of H atoms.Meanwhile,the introduction of P increased the active site and intrinsic activity.

关 键 词：电解水 氢析出反应 磷化钯 电催化 

分 类 号：TQ116.21[化学工程—无机化工] TQ426