Fang Renjie, He Haoxian, Wang Zhiyi, Han Ye-Chuang, Fan Feng Ru
State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen 361005, China.
Mater Horiz. 2024 Jul 29;11(15):3595-3603. doi: 10.1039/d4mh00225c.
The synthesis of phase-pure carbide nanomaterials is crucial for understanding their structure-performance relationships, and for advancing their application in catalysis. Molybdenum carbides, in particular, have garnered increasing interest due to their Pt-like surface electronic properties and high catalytic activity. Traditional methods for synthesizing molybdenum carbide are often lengthy and energy-intensive, leading to an uncontrolled phase, low purity, and excessive carbon coverage, which hinder their catalytic performance improvement. This work introduces a novel pulsed Joule heating (PJH) technique that overcomes these limitations, enabling the controlled synthesis of high-purity molybdenum carbides (β-MoC, η-MoC, and α-MoC) within seconds by using MoO/4-Cl--phenylenediamine as the hybrid precursor. The PJH method allows precise control over the diffusion of carbon species in the Mo-C system, resulting in a significantly improved phase purity of up to 96.89 wt%. Moreover, the electronic structure of platinum catalysts on molybdenum carbide was modulated through electron metal-support interaction (EMSI) between Pt and MoC, and contributed to enhanced catalytic performance compared to carbon-supported Pt catalysts during the hydrogen evolution reaction. Overall, this work paves the way for efficient production of high-quality molybdenum carbide nanomaterials, and thus is expected to accelerate their industrial deployments in practical catalytic reactions.
合成纯相碳化物纳米材料对于理解其结构-性能关系以及推动其在催化领域的应用至关重要。特别是碳化钼，由于其类似铂的表面电子性质和高催化活性而受到越来越多的关注。传统的合成碳化钼的方法通常耗时且耗能，导致相态失控、纯度低以及碳覆盖过度，这阻碍了它们催化性能的提升。这项工作引入了一种新颖的脉冲焦耳加热（PJH）技术，该技术克服了这些限制，通过使用MoO/4-Cl- -苯二胺作为混合前驱体，能够在几秒钟内可控地合成高纯度的碳化钼（β-MoC、η-MoC和α-MoC）。PJH方法允许精确控制碳物种在Mo-C体系中的扩散，从而使相纯度显著提高，高达96.89 wt%。此外，通过Pt与MoC之间的电子-金属-载体相互作用（EMSI）调节了碳化钼上铂催化剂的电子结构，与碳载铂催化剂相比，在析氢反应过程中有助于提高催化性能。总体而言，这项工作为高效生产高质量的碳化钼纳米材料铺平了道路，因此有望加速它们在实际催化反应中的工业应用。
