木质素磺酸钠衍生S/N共掺杂电催化剂结构调控与OER性能研究  

Structure Engineering of Lignosulfonate-derived S/N Co-doped Catalyst for Electrocatalytic OER Performance

作　　者：王晓菲 薛李静 周海潮 林绪亮 邱学青 Wang Xiao-fei;Xue Li-jing;Zhou Hai-chao;Lin Xu-liang;Qiu Xue-qing(Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory,Jieyang 515200,China;School of Chemical Engineering and Light Industry,Guangdong University of Technology,Guangzhou 510006,China;Guangdong Provincial Key Laboratory of Plant Resources Biorefinery,Guangdong University of Technology,Guangzhou 510006,China)

机构地区：[1]化学与精细化工广东省实验室揭阳分中心,广东揭阳515200 [2]广东工业大学轻工化工学院,广东广州510006 [3]广东工业大学广东省植物资源生物炼制重点实验室,广东广州510006

出　　处：《广东工业大学学报》2023年第6期95-105,共11页Journal of Guangdong University of Technology

基　　金：国家自然科学基金资助项目(22038004,22178069);广东省重点领域研发计划项目(2020B1111380002)。

摘　　要：析氧反应(Oxygen Evolution Reaction,OER)是电催化水分解能源转化过程的核心与速控步骤,较高的反应能垒导致动力学缓慢,限制了整体效率。本文基于可再生的木质素磺酸钠原料,依次采用氧化氨解、配位自组装、原位碳化制备了双金属硫化物Co_(9)S_(8)-Ni_(3)S_(2)/SN-C催化剂,表现出优异的电催化OER性能。结合全面表征明确了氧化氨解得到的酰胺基团改性木质素磺酸钠与金属间的络合结构,并揭示了前驱体在热解碳化过程中的结构演变机制,以及活性中心Co_(9)S_(8)-Ni_(3)S_(2)的形成过程。在改性木质素衍生碳的强结合作用下,金属分散度提高。Co_(9)S_(8)-Ni_(3)S_(2)二者的紧密作用以及N对碳载体的缺陷掺杂,有效调控催化剂表面电子结构,优化中间体的吸附,进而提升了电催化OER反应性能。当氧化氨解过程中m(H2O2)/m(LS)=1.5时,Co_(9)S_(8)-Ni_(3)S_(2)/SN-C催化剂的OER活性最高,在50mA·cm^(-2)的电流密度下,相比商业催化剂Ru/C(420 mV)具有更低的过电位(350 mV)。该工作为木质素碳材料的定向调控以及高效稳定OER电催化剂的开发提供了新思路。Oxygen evolution reaction(OER)is a core and rate-control process for the electrocatalytic water splitting.Due to the high energy barrier,the OER kinetics and overall water splitting efficiency are limited.Herein,bimetallic sulfide Co_(9)S_(8)-Ni_(3)S_(2)/SN-C catalyst was successfully prepared via oxidative ammonolysis of renewable lignosulfonates,and showed excellent electrocatalytic OER performance.The complex structure of sodium lignosulfonate modified with NHCO groups was investigated by comprehensive characterization,and the structural evolution mechanism of the precursor during pyrolysis and carbonization was revealed,with the formation of the active center Co_(9)S_(8)-Ni_(3)S_(2) revealed as well.The strong binding of the modified lignin-carbon with metals enhanced the dispersion of active sites Co_(9)S_(8) and Ni_(3)S_(2).The close interaction between Co_(9)S_(8)-Ni_(3)S_(2) and the defect doping of N onto the carbon carrier effectively regulated the surface electronic structure,and optimized the adsorption of the reaction intermediate,and thus improved the electrochemical OER reaction performance.The OER activity of Co_(9)S_(8)-Ni_(3)S_(2)/SN-C catalyst reached the highest level when m(H2O2)/m(LS)=1.5 for oxidative ammonolysis,and showed a lower overpotential(350 mV)than that of commercial Ru/C catalyst(420 mV)at a current density of 50 mA·cm^(-2).This work provides an insight into the directional regulation of lignin-based functional materials and its development for highly efficient and stable OER electrocatalysis.

关 键 词：木质素 氧化氨解 电解水 析氧反应 过渡金属硫化物 

分 类 号：TQ151[化学工程—电化学工业] TQ351