Pt/TS-1 Catalyst Promoted C-N Coupling Reaction in CH4-NH3 Plasma for HCN Synthesis at Low Temperature

Hydrocyanic acid is an important synthetic material in chemical industry. Currently, the industrial methods of producing HCN mainly include the Andrussow and BMA processes, which are necessarily operated at temperatures of more than 1000 degrees C. This paper proposes a method to synthesize HCN at low temperature (400 degrees C) through a C-N coupling reaction in CH4/NH3 nonthermal plasma with the assistance of Pt/TS-1 catalyst. Under the optimized reaction conditions (CH4/NH3 = 1:2, GHSV: 2425 s(-1), discharge length: 3 cm, reaction temperature: 400 degrees C, Pt/TS-1 + plasma), 80.9% HCN selectivity was achieved with 25.9% CH4 conversion. During the reaction process, the nonthermal plasma played a role of activating CH4 and NH3 into radical species (CHx and NHy), while the Pt/TS-1 catalyst promoted the C-N coupling reaction of the radical species to produce HCN.