中国海洋大学董博华团队报道了将超细纳米合金与无定形表层接枝，实现高活性和长寿命的酸性氢气生产。相关论文于2024年2月3日发表在《德国应用化学》杂志上。

质子交换膜水电解（PEM-WE）的大规模应用需要大幅减少作为阴极析氢反应（HER）不可或缺的，电催化剂铂族金属（PGMs）的使用。超细PGMs纳米催化剂在较低的负载量下具有丰富的催化位点，但在腐蚀性酸性环境下的长期操作中通常表现出降低的稳定性。

该文中，研究人员报道了通过原位原子层硒化用PtxRuySez“无定形表层”接枝超细PtRu晶体纳米合金(c-PtRu@a-PtxRuySez)，同时提高催化活性和稳定性。研究发现c-PtRu@a-PtxRuySez-1具有约0.6 nm厚度的无定形表层在0.07 V下实现了26.7 A mg^-1Pt+Ru的超高质量活性，并且对于酸性HER在10 mA cm^-2下保持至少1000小时和在100 mA·cm^-2下保持550小时的最先进的耐久性。

实验和理论研究表明，无定形表层不仅提高了催化剂表面的电化学可及性，增加了催化位点的固有活性，而且减轻了活性物质的溶解/扩散，从而提高了在酸性电解质下的催化活性和稳定性。

该项工作展示了设计具有高利用率和耐用度的超细PGM电催化剂的方向，提供了一种原位“无定形表层”工程策略。

附：英文原文

Title: Grafting Ultra-fine Nanoalloys with Amorphous Skin Enables Highly Active and Long-lived Acidic Hydrogen Production

Author: Biao Zeng, Xinzheng Liu, li Wan, Chenghui Xia, Lixin Cao, Yubin Hu, Bohua Dong

Issue&Volume: 2024-02-03

Abstract: Large-scale deployment of proton exchange membranes water electrolysis (PEM-WE) requires a substantial reduction in usage of platinum group metals (PGMs) as indispensable electrocatalyst for cathodic hydrogen evolution reaction (HER). Ultra-fine PGMs nanocatalysts possess abundant catalytic sites at lower loading, but usually exhibit reduced stability in long-term operations under corrosive acidic environments. Here we report grafting the ultra-fine PtRu crystalline nanoalloys with PtxRuySez “amorphous skin” (c-PtRu@a-PtxRuySez) by in situ atomic layer selenation to simultaneously improve catalytic activity and stability. We found that the c-PtRu@a-PtxRuySez-1 with ~ 0.6 nm thickness amorphous skin achieved an ultra-high mass activity of 26.7 A mg1Pt+Ru at 0.07 V as well as a state-of-the-art durability maintained for at least 1000 h at 10 mA cm2 and 550 h at 100 mA·cm2 for acid HER. Experimental and theoretical investigations suggested that the amorphous skin not only improved the electrochemical accessibility of the catalyst surface and increasing the intrinsic activity of the catalytic sites, but also mitigated the dissolution/diffusion of the active species, thus resulting in improved catalytic activity and stability under acidic electrolyte. This work demonstrates a direction of designing ultra-fine PGMs electrocatalysts both with high utilization and robust durability, offers an in situ “amorphous skin” engineering strategy.

DOI: 10.1002/anie.202400582

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202400582