Bai Sitian, Mou Yiwei, Wan Jin, Wang Yanwei, Li Weibo, Zhang Huijuan, Luo Ping, Wang Yu
The School of Chemistry and Chemical Engineering, State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, 174 Shazheng Street, Shapingba District, Chongqing City, 400044, PR China.
The School of Electrical Engineering, Chongqing University, 174 Shazheng Street, Shapingba District, Chongqing City, 400044, PR China.
Nanoscale. 2022 Dec 15;14(48):18123-18132. doi: 10.1039/d2nr05167b.
Designing amorphous/crystalline heterophase catalysts is still in the initial stage, and the study of amorphous/crystalline heterophase and carbon-free catalysts has not yet been realized. Herein, we report a unique amorphous/crystalline heterophase catalyst consisting of NiFe alloy nanoparticles (NPs) supported on TiO (NiFe/TiO) for the first time, which is achieved by a heterophase supporting strategy of dual heat treatment. Surprisingly, the amorphous/crystalline heterophase is flexibly composed of amorphous and crystalline phases of alloy NPs and TiO. The heterophase coupling endows the catalyst with a low overpotential (256 mV at 10 mA cm), a small Tafel slope (47 mV dec) and excellent endurance stability (over 100 h) in 1 M KOH electrolyte, which already outperforms commercial RuO (338 mV and 113 mV dec) and exceeds most reported representative carbon-based and titanium-based non-precious metal catalysts. The density functional theory (DFT) calculations and experimental results reveal that the unique amorphous/crystalline heterophase coupling in NiFe/TiO results in electron transfer between the alloy NPs and TiO, allowing more catalytically active sites and faster interfacial electron transfer dynamics. This work provides insights into the synthesis of amorphous/crystalline heterophase catalysts and can be generalized to the heterophase coupling of other transition metal-based electrocatalysts.
设计非晶态/晶态异相催化剂仍处于初始阶段，且尚未实现对非晶态/晶态异相及无碳催化剂的研究。在此，我们首次报道了一种独特的由负载在TiO上的NiFe合金纳米颗粒（NPs）组成的非晶态/晶态异相催化剂（NiFe/TiO），这是通过双重热处理的异相负载策略实现的。令人惊讶的是，非晶态/晶态异相由合金NPs和TiO的非晶态和晶态相灵活组成。这种异相耦合赋予催化剂在1 M KOH电解液中具有低过电位（10 mA cm时为256 mV）、小塔菲尔斜率（47 mV dec）和优异的耐久性稳定性（超过100小时），其性能已超过商业RuO（338 mV和113 mV dec），并超过了大多数已报道的代表性碳基和钛基非贵金属催化剂。密度泛函理论（DFT）计算和实验结果表明，NiFe/TiO中独特的非晶态/晶态异相耦合导致合金NPs和TiO之间的电子转移，从而产生更多的催化活性位点和更快的界面电子转移动力学。这项工作为非晶态/晶态异相催化剂的合成提供了见解，并可推广到其他过渡金属基电催化剂的异相耦合。
