Liu Jianglin, Zhang Jinhui, Zhou Haichao, Liu Bowen, Dong Huafeng, Lin Xuliang, Qin Yanlin
Guangdong Provincial Key Laboratory of Plant Resources Biorefinery, School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China.
School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou 510006, China.
J Colloid Interface Sci. 2023 Jan;629(Pt A):822-831. doi: 10.1016/j.jcis.2022.08.141. Epub 2022 Aug 28.
Developing noble-metal-free electrocatalysts for efficient oxygen evolution reactions (OER) is urgently desired to obtain green hydrogen by water electrolysis. Coupling FeNi catalysts with other transition metals is an effective strategy to improve the OER performance, but the electronic structure regulation of the catalytic center is challenging. Herein, heterostructures catalyst composed of MoC and FeNi alloy embedded in N-doped biochar (denoted as MoC-FeNi@NLC) was in situ synthesized by pyrolysis of lignin-metals coordination complex. MoC-FeNi@NLC displayed an overpotential of 198 mV and a long steady running time of 200 h at 10 mA·cm in alkaline media. Furthermore, MoC-FeNi@NLC has demonstrated excellent Faradaic efficiency (FE) of over 90 %. A voltage of 1.50 V was required based on the MoC-FeNi@NLC and Pt/C coupling system, which was superior to that of commercial noble metal catalysts (Pt/C || Ir/C, 1.57 V). The density functional theory demonstrated that FeNi alloy balanced the adsorption energy of OER intermediates and regulated the orbital overlap of Mo above Fermi level. While the lignin-derived carbon layer prevented the deactivation and dissolution of catalytic center. The construction strategy of transition metal alloys and carbides heterojunction by the assistance of sustainable lignin derivatives and its structure-activity relationship toward OER electrocatalytic process provides a promising and cost-efficient pathway for the design of high-performance and stable OER catalysts.
迫切需要开发用于高效析氧反应（OER）的无贵金属电催化剂，以通过水电解获得绿色氢气。将FeNi催化剂与其他过渡金属耦合是提高OER性能的有效策略，但催化中心的电子结构调控具有挑战性。在此，通过木质素-金属配位络合物的热解原位合成了由嵌入N掺杂生物炭中的MoC和FeNi合金组成的异质结构催化剂（表示为MoC-FeNi@NLC）。MoC-FeNi@NLC在碱性介质中，在10 mA·cm²下显示出198 mV的过电位和200 h的长稳定运行时间。此外，MoC-FeNi@NLC表现出超过90%的优异法拉第效率（FE）。基于MoC-FeNi@NLC和Pt/C耦合系统需要1.50 V的电压，这优于商业贵金属催化剂（Pt/C || Ir/C，1.57 V）。密度泛函理论表明，FeNi合金平衡了OER中间体的吸附能，并调节了费米能级以上Mo的轨道重叠。而木质素衍生的碳层防止了催化中心的失活和溶解。借助可持续的木质素衍生物构建过渡金属合金和碳化物异质结的策略及其对OER电催化过程的结构-活性关系，为设计高性能和稳定的OER催化剂提供了一条有前景且具有成本效益的途径。
