Zheng Long, Zhang Yan, Chen Weiwei, Xu Xiangou, Zhang Ruiqi, Ren Xiao, Liu Xiaozhi, Wang Wenbin, Qi Junlei, Wang Gang, Ma Chen, Xu Lei, Han Peng, He Qiyuan, Ma Ding, Wang Jinlan, Ling Chongyi, Su Dong, Shao Minhua, Chen Ye
Department of Chemistry, The Chinese University of Hong Kong, Hong Kong, China.
Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
Angew Chem Int Ed Engl. 2025 Jun 2;64(23):e202500985. doi: 10.1002/anie.202500985. Epub 2025 Apr 7.
Phase engineering plays a crucial role in tuning the physicochemical properties of noble metal nanomaterials. However, synthesis of high-purity unconventional-phase noble metal nanomaterials remains highly challenging via current wet-chemical methods. Herein, we develop a unique synthetic methodology to prepare freestanding unconventional hexagonal close-packed (2H) Rh nanoplates (NPLs) via a rationally designed two-step strategy. By extracting C from pre-synthesized rhodium carbide of different sizes and morphology, phase-controlled synthesis of Rh nanomaterials can be achieved. Impressively, the obtained parallelogram 2H Rh NPLs have high phase purity, well-defined 2H (0001) and (10 0) facets, and good thermostability (stable up to 300 °C). In the proof-of-concept electrocatalytic nitrate reduction reaction (NORR), the 2H Rh NPLs achieve higher ammonia (NH) Faradaic efficiency (91.9%) and NH yield rate (156.97 mg h mg ) with lower overpotentials compared to the conventional face-centered cubic (3C) Rh nanocubes with (100) facets. Density functional theory calculations reveal that the unconventional (0001) surface has energetically favored NORR pathway and stronger H absorption ability compared to the (100) surface, which may lead to the higher activity and selectivity of NH production on 2H Rh NPLs. This work opens new avenues to the rational synthesis of unconventional-phase metal nanomaterials and provides important guidelines to design high-performance electrocatalysts.
相工程在调控贵金属纳米材料的物理化学性质方面起着至关重要的作用。然而，通过当前的湿化学方法合成高纯度的非常规相贵金属纳米材料仍然极具挑战性。在此，我们开发了一种独特的合成方法，通过合理设计的两步策略制备独立的非常规六方密排（2H）铑纳米片（NPLs）。通过从预合成的不同尺寸和形态的碳化铑中提取碳，可以实现铑纳米材料的相控合成。令人印象深刻的是，所获得的平行四边形2H铑NPLs具有高相纯度、明确的2H（0001）和（10 0）晶面以及良好的热稳定性（在高达300°C时稳定）。在概念验证的电催化硝酸盐还原反应（NORR）中，与具有（100）晶面的传统面心立方（3C）铑纳米立方体相比，2H铑NPLs在较低过电位下实现了更高的氨（NH）法拉第效率（91.9%）和NH产率（156.97 mg h mg）。密度泛函理论计算表明，与（100）表面相比，非常规的（0001）表面具有能量上有利的NORR途径和更强的H吸收能力，这可能导致2H铑NPLs上NH生成具有更高的活性和选择性。这项工作为非常规相金属纳米材料的合理合成开辟了新途径，并为设计高性能电催化剂提供了重要指导。
