“…It is worth noting that the catalyst obtained without the molten salt method is MoO 2 , which indicates that the molten salt method can promote the carburization reaction, so that the carbon in the Mo-precursor can penetrate into the lattice gap of Mo and finally form stable molybdenum carbide. 28 As shown in Fig. S3,† the characteristic peaks of MoO 2 -900 are 26.0°, 36.8°, 37.0°, 37.4°, 53.1°, 53.5°, 60.2°, 66.7°, 78.5° and 79.3° corresponding to the (−1 1 1), (2 0 0), (−2 1 1), (−2 0 2), (2 2 0), (−3 1 2), (0 3 2), (−4 0 2), (2 3 1) and (−2 3 3) crystal planes of MoO 2 (JCPDS NO 32-0671).…”