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Graphical abstract Highlights • CVD temperature has a significant effect on the structure of the formed carbon. • Graphene-like carbon films can be fabricated at low CVD temperatures. • The graphene-like films show similar structure of reduced graphene oxides. • Graphene-like carbon films possess enhanced reactivity with hydrogen and CO 2. Abstract The formation and reactivity of carbon on the supported nickel catalyst is a key issue for the low temperature activity and stability with methanation, reforming and other reactions. In this work, Ni(1 1 1)/TiO 2 was prepared and applied as the catalyst to deposit carbon using low temperature chemical vapor deposition (CVD) of carbon monoxide. It was found that the CVD temperature could significantly affect the formation of carbon. With the CVD temperature decreasing, the disorder of the carbon increased, while the degree of graphitization was reduced. As a result, graphene-like films can be obtained at low CVD temperatures (from 300 to 350 °C). Such carbon films show a significantly improved reactivity with hydrogen and carbon dioxide. This explains the excellent low temperature activity and stability for CO 2 or CO methanation over Ni catalysts with Ni(1 1 1). [ABSTRACT FROM AUTHOR]

Based on the synergy between MoP and N-doped carbon, MoP nanoparticles encapsulated in N-doped carbon hollow spheres were synthesized using inorganic-organic hybrids as precursors, which shows an excellent stability and activity with an overpotential 96 mV at 10 mA cm−2 and a small Tafel slope of 53 mV dec−1 in alkaline solution. [Display omitted] • A template-free approach was developed to fabricate MoP@NC hollow microsphere. • Inorganic-organic hybrids were used as precursors. • Remarkable electrocatalytic hydrogen evolution performance could be achieved. • The synergy between MoP and the pyridinic N could optimize the electronic structure. Encapsulating transition metal phosphides into nitrogen-doped carbon (NC) materials is an effective strategy to enhance the electrocatalytic performance. Herein, we develop a novel template-free approach to rationally fabricate molybdenum phosphide (MoP) nanoparticles encapsulated in N-doped carbon (MoP@NC) hollow microspheres for alkaline hydrogen evolution reaction (HER) by employing inorganic-organic hybrids as precursors, in which phosphorus source of the MoP@NC derives from tetra (hydroxymethyl) phosphorus chloride for the first time. The optimized MoP@NC sample shows a low overpotential of 96 mV at 10 mA cm−2, a small Tafel slope of 53 mV dec−1, and excellent stability. The enhanced HER performance is mainly attributed to the integrated effects of a distinctive hollow structure, high pyridinic N-doping level, and the extremely intimate synergy between MoP and NC. Theoretical calculations indicate that the active sites of the catalyst are mainly located at Mo atoms adjacent to the pyridinic N-doped carbon layer (pyridinic-N-MoP); the synergistic interaction between MoP and pyridinic N (rather than pyrrolic or graphitic N) atoms can lower the d band center of Mo, weaken the Mo-H ads bond and thereby enhance HER performance. In addition, the pyridinic N atoms at the interactive sites play a key role in adsorbing H 2 O and preventing the adsorption of OH*, resulting in accelerating the water splitting. This work provides a new method to rationally synthesize high-efficient and stable MoP-based hollow sphere electrocatalysts for alkaline HER through designing inorganic-organic hybrid precursors. [ABSTRACT FROM AUTHOR]