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• WC-Co composite powder is synthesized by employing successive liquid methanol. • Carbon nanolayers loaded on the intermediates prevent particle aggregation of WC-Co. • WC-Co composite powder with clean surface is no need for washing with water or acid. • WC-Co composite powder possesses controllable carbon content. Tungsten carbide-cobalt (WC-Co) mixtures is the most critical material for cemented carbide. However, traditional preparation methods by using various carbon sources (e. g. carbon black, glucose, methane, carbon monoxide) cause severe carbon deposition. Consequently, traditional WC-Co mixtures exhibits uncontrollable carbon content. To address the challenge, we investigate the in-situ synthesis of WC-Co mixtures by supplying successive liquid methanol as a carbon source and nitrogen gas as a diluent. The as-prepared WC-Co mixture possesses clean surface and controllable carbon content, which are no need for removing excess carbon deposition by washing with water. The carbon nanolayers derived from methanol cracking gas appear on the surface of the intermediates, which can effectively prevent particle aggregation, efficiently increase the intimate contact probability of WC particles and Co particles, and greatly reduce the appearance of excess carbon deposition during subsequent carbonization processes. The present study offers insights on employing quantitative methanol cracking gas as reductive and carbonaceous atmosphere to mediate carbon content in the WC-Co composite powder, which presents a more economical and efficient pathway for large-scale synthesis of high-quality WC-Co mixtures with clean surface and controllable carbon content. [ABSTRACT FROM AUTHOR]

The tungsten carbide can be used as the template to produce the ultrathin and coiled carbon nanosheets (UC-CNS) repeatedly. The UC-CNS loaded Pt NPs displays high electrochemical properties and excellent stability. • The UC-CNS could be stripped away from the WC substrate without obvious destruction. • The UC-CNS possessed high degree of graphitization and high specific surface area. • The UC-CNS/Pt displayed high electrochemical activity and excellent stability. • Excellent activity was ascribed to strong interaction between UC-CNS and Pt. Highly graphitic carbon nanomaterials with large specific surface area and good dispersion are very favorable supports for Pt-based catalysts in fuel cells. Ultrathin and coiled carbon nanosheets (UC-CNS) were successfully synthesized via chemical vapor deposition method using tungsten carbide (WC) as substrate. After the WC@UC-CNS was immersed in HF/HNO 3 /H 2 O solution, UC-CNS was completely stripped away from the WC substrate without obvious destruction, and possessed coiled edges and more oxygen-containing functional groups for anchoring Pt nanoparticles. Another obtained product (WO 3) could be used as a tungsten source to produce UC-CNS repeatedly. The purified UC-CNS, with thicknesses of 3.45–5.61 nm, possessed high specific surface area (547 m2 g−1) and high degree of graphitization (I G /I D =1.43). Pt loaded on the UC-CNS exhibited high electrocatalytic activity and extremely high stability for methanol oxidation reaction even after 14,000 potential cycles. We believe UC-CNS can be widely used in fuel cells and other related green chemical applications. [ABSTRACT FROM AUTHOR]