Solar-heating thermocatalytic H production from formic acid by a MoS-graphene-nickel foam composite

Sunlight driven formic acid decomposition has great potential to supply high-purity H 2 without consuming fossil fuel-derived energy. However, a trace amount of CO invariably exists in the obtained H 2 and the H 2 production rate is always lower than 278 mmol g −1 h −1 . Here, we found that high quality MoS 2 grown on graphene decorated on Ni foam (Ni/G/MoS 2 ) was active and stable for H 2 production from thermocatalytic formic acid decomposition without CO presentation and first principles calculation confirmed that the perfect surface terminating sulfur of MoS 2 changed the reaction path of intermediates, thus inhibiting the production of CO. Furthermore, a reaction device constructed with Cu 2 Se can heat catalysts to 120 and 260 °C under 0.25 kW m −2 and 1 kW m −2 (1 Sun) of irradiation, respectively. By using the system of the Cu 2 Se based reaction device and Ni/G/MoS 2 , a CO free H 2 production rate of 982 mmol g −1 h −1 was achieved under 0.6 Sun of irradiation, 3.5 times higher than the previous record of photocatalytic formic acid decomposition. Therefore, this work provides a new viewpoint for large scale CO free H 2 production in a sustainable and green way. Using a combination of Ni/G/MoS 2 and a Cu 2 Se based reaction device, a CO free H 2 production rate of 982 mmol g −1 h −1 was achieved under 0.6 Sun of irradiation, 3.5 times higher than the previous record of photocatalytic formic acid decomposition.