Solar heating catalytic formic acid dehydrogenation by graphene-porous foam-supported tungsten nitride nanoparticles

Abstract

The discovery of highly efficient and selective non-precious metal catalysts for the dehydrogenation of formic acid (FA) is crucial for the generation of clean hydrogen (H₂). Here, we present a facile method for the synthesis of graphene-porous foam-supported dispersed tungsten nitride nanoparticles (WN/Gr PF), which exhibit significant thermal catalytic activity in FA dehydrogenation, with an H₂ yield of 7.88 L g⁻¹ h⁻¹ at 300 °C, suggesting the promising application potential of tungsten-based catalysts in FA dehydrogenation. The stepwise FA dehydrogenation mechanism on the hybrid is investigated via in situ diffuse reflectance infrared Fourier transform spectroscopy. Meanwhile, because this reaction requires a heating temperature, combining a FA dehydrogenation reactor with a solar heating device may be beneficial for industrial applications. Thus, a solar-heating FA dehydrogenation system is constructed, integrating a Ti₂O₃/Cu-based solar heating apparatus and the hybrid. This system can achieve a temperature of up to 294 °C and an H₂ production rate of 7.60 L g⁻¹ h⁻¹ from FA dehydrogenation under 0.4 kW m⁻². This rate exceeds those of other efficient catalysts previously reported for photocatalytic FA dehydrogenation. This solar heating catalytic model offers a fossil-energy-free way to practicalize the generation of H₂ from FA under solar irradiation.