提升Pd基电催化剂氧还原活性的策略

氧还原反应(ORR)是许多电化学相关技术的核心反应,许多研究致力于制备同时具备高活性、高稳定性和低成本的催化剂。Pd基纳米材料由于其相对较优的催化性能和相对丰富的储量,有望成为Pt的替代品,受到了广泛关注,但要达到商品化程度,其性能需进一步提高。本文以Pd基催化剂应用于ORR电催化为背景,综述了近年来Pd基催化剂ORR的性能提升策略。围绕载体调控、形貌结构调控以及组分调控共3个部分进行总结,这些调控会利用配体效应、应变效应、系综效应(ensemble effect)和载体效应等从本质上改变Pd的分布状态、空间排列和电子结构,从而影响ORR中间产物在Pd表面的吸附状态。最后,简要介绍了Pd基催化剂面临的挑战和未来的发展方向,对高性能ORR催化剂的设计制备具有重要意义。

Strategies for boosting the catalytic performance of palladium-based electrocatalysts for oxygen reduction reaction

Oxygen reduction reaction is the key reaction of many electrochemical devices and technologies, and massive and increasing efforts have been devoted to develop more efficient ORR electrocatalysts in recent decades. Owing to its analogous physical properties to Pt, e.g. phase structure, atomic size and electronic configuration as well as its higher abundance in earth, palladium(Pd)-based nanomaterials, which have been regarded as good substitutes for platinum(Pt), have been extensively studied and their electrocatalytic performance for ORR is continuously improved. Herein, we focus this review on the strategies developed in recent years for boosting the catalytic performance of Pd-based electrocatalysts for ORR, including substrate tailoring, morphological control and composition optimization. These strategies would alter the electronic coupling, ligand effect, lattice strain, and synergistic effect around the Pd atoms, equipping them favorable features for catalyzing oxygen reduction. In the final section of this review, we put forth some perspectives/challenges for further development of Pd-based electrocatalysts, which might be helpful for designing and fabrication of high-efficiency ORR catalysts.