Ma Tian, Cao Hao, Li Shuang, Cao Sujiao, Zhao Zhenyang, Wu Zihe, Yan Rui, Yang Chengdong, Wang Yi, van Aken Peter A, Qiu Li, Wang Yang-Gang, Cheng Chong
College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Department of Ultrasound, West China Hospital, Sichuan University, Chengdu, 610041, China.
Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China.
Adv Mater. 2022 Oct;34(41):e2206368. doi: 10.1002/adma.202206368. Epub 2022 Sep 4.
Platinum-based catalysts occupy a pivotal position in diverse catalytic applications in hydrogen chemistry and electrochemistry, for instance, the hydrogen evolution reactions (HER). While adsorbed Pt atoms on supports often cause severe mismatching on electronic structures and HER behaviors from metallic Pt due to the different energy level distribution of electron orbitals. Here, the design of crystalline lattice-confined atomic Pt in metal carbides using the Pt-centered polyoxometalate frameworks with strong PtO-metal covalent bonds is reported. Remarkably, the lattice-confined atomic Pt in the tungsten carbides (Pt @WC , both Pt and W have atomic radii of 1.3 Å) exhibit near-zero valence states and similar electronic structures as metallic Pt, thus delivering matched energy level distributions of the Pt 5d 2 and H 1s orbitals and similar acidic hydrogen evolution behaviors. In alkaline conditions, the Pt @WC exhibits 40 times greater mass activity (49.5 A mg at η = 150 mV) than the Pt@C because of the favorable water dissociation and H* transport. These findings offer a universal pathway to construct urgently needed atomic-scale catalysts for broad catalytic reactions.
铂基催化剂在氢化学和电化学等多种催化应用中占据关键地位，例如析氢反应（HER）。然而，由于电子轨道能级分布不同，负载在载体上的吸附态铂原子往往会导致电子结构和HER行为与金属铂存在严重不匹配。在此，报道了利用具有强PtO - 金属共价键的以铂为中心的多金属氧酸盐框架，在金属碳化物中设计晶格受限的原子级铂。值得注意的是，碳化钨中的晶格受限原子铂（Pt@WC，Pt和W的原子半径均为1.3 Å）呈现出接近零的价态以及与金属铂相似的电子结构，从而实现了Pt 5d 2和H 1s轨道匹配的能级分布以及相似的酸性析氢行为。在碱性条件下，由于良好的水离解和H*传输，Pt@WC的质量活性（在η = 150 mV时为49.5 A mg）比Pt@C高40倍。这些发现为构建广泛催化反应急需的原子级催化剂提供了一条通用途径。
