Reduction of supported GaN and its application in methane conversion

The reduction of supported GaN using amorphous SiO2, silicalite-1 (S1), and HZSM-5 (HZ) as the carriers was investigated and tested for methane conversion to acetonitrile (ACN). Ammonia nitridation was used to synthesize GaN samples. The highest ammonia and ACN productivities (433 and 383 mmol/g, respectively) were obtained by using 5 wt% GaN on HZ (5GaN/HZ). The N-Ga interaction of 5GaN/HZ was discovered to be weakened due to the presence of a neighboring Bronsted acid. The oxidation state of gallium was reduced during methane conversion, implying the loss of nitrogen from GaN. The decreased activity could be rejuvenated by a renitridation step. The GaN surface structures, including the adsorption surface, (110), and the side surfaces, (001), (110), (111), and (111), were calculated via first-principles calculations. Among them, the (001) side surface of GaN was likely to be the origin of mobile nitrogen, which is important in the conversion of methane to ACN.(c) 2023 Elsevier Ltd. All rights reserved.