(666f) Electrochemical Synthesis of Aniline Using Ammonia and Benzene

Aniline is a vital intermediate with a plethora of applications ranging from rubber accelerators, and antioxidants to numerous dyes. Fossil-fuel-based production of Aniline uses 0.3 EJ of energy annually.¹ Moreover, the consumption of ammonia for electrochemical synthesis of value-added products is of great interest to decarbonize aniline production. The Electrochemical synthesis of aniline polymers and resin has been greatly explored, but it requires aniline as one of the starting reactants, although limited works have been reported in the domain of electrochemical aniline synthesis. In this study, ammonia and benzene are used to synthesize Aniline. It is presumed that ammonia will be produced using renewable energy. Various transition metals like Silver, copper, cobalt, and nickel are explored as potential catalysts as they are previously shown to facilitate the formation of the C-N bond which goes through nitrate to ammonia to imines. Silver has been identified as the most promising catalyst because it had the best kinetics and was the most active catalyst as compared to other transition metals.² The system was optimized by varying electrolyte constitutions, counter cations, and supporting electrolyte anions to obtain better faradaic efficiency, current densities, and selectivity. NMR is used to quantify the aniline concentration in the product solution.

References

1. B. Winter, R. Meys, André B. Towards aromatics from biomass: Prospective Life Cycle Assessment of bio-based aniline, Journal of Cleaner Production, 290, 2021, 125818

2. Zachary J Schiffer, Minju Chung, Katherine Steinberg, Karthish Manthiram, Selective electrochemical reductive amination of benzaldehyde at heterogeneous metal surfaces, Chem Catalysis, 3, 2, 2023, 100500