Tungsten carbide hollow microspheres as electrocatalyst and platinum support for hydrogen evolution reaction

• Synthesis temperature is crucial to products' compositions and surface states, and has great influences to HER ability.
• The optimal synthesis temperature is 1223 K, excessive synthesis temperature is detrimental to HER ability.
• As-synthesized WC possesses spherical hollow microstructure, which is considered to be beneficial to its electrocatalytic ability.
• The bulk WChs displays excellent HER activity.

Tungsten carbide with special spherical hollow microstructure was synthesized and tested as an electrocatalyst or electrocatalysts support for platinum. Both bulk WC and as-synthesized WC supported Pt were evaluated as hydrogen evolution catalysts. It was found that the synthesis temperature is crucial to the compositions and surface states of products, and has direct influence on HER activity. The WC possesses spherical micro-morphology with a high specific surface area, and its hollow and cracked structural features are considered to be beneficial for its electrocatalytic ability and potential as electrocatalysts support. The bulk WC hollow microspheres displayed excellent HER activity. The 20% Pt/WC also exhibited better electrocatalytic performance than the commercial 20% Pt/C: the current density has obviously increased, and the kinetic parameters such as Tafel slope and exchange current density have obvious improvement as well. The investigations indicated that the as-synthesized WC could be considered as a potential electrocatalyst and electrocatalyst support.