Rapid synthesis of high-purity molybdenum carbide with controlled crystal phases

• Published in: Materials horizons Vol. 11; no. 15; pp. 3595 - 3603
• Main Authors: Fang, Renjie, He, Haoxian, Wang, Zhiyi, Han, Ye-Chuang, Fan, Feng Ru
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 29.07.2024
• Subjects: Carbon; Catalysis; Catalysts; Catalytic activity; Chemical synthesis; Electronic properties; Electronic structure; Hybrid systems; Hydrogen evolution reactions; Molybdenum; Molybdenum carbide; Nanomaterials; Ohmic dissipation; Phenylenediamine; Purity; Resistance heating; Species diffusion
• ISSN: 2051-6347; 2051-6355; 2051-6355
• 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-Mo C, 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 Mo C, 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.