Acetonitrile formation from ethane or ethylene through anaerobic ammodehydrogenation

The on-purpose production of acetonitrile from ethane or ethylene through conventional aerobic ammoxidation faces the challenge of CO 2 and NO x formation. Here we show an anaerobic ammodehydrogenation (ADeH) process for acetonitrile formation from ethane or ethylene. For ethane ADeH, we identified that among various second metal promoters (Co, Zn, Ga, In, Sn, Ce, Rh, Zr, Mn, and Pd), only Co demonstrated a promising promotion effect on the benchmark Pt/HZSM-5 (SiO 2 /Al 2 O 3 = 30) catalyst. We show that the presence of Co enhanced the activity, selectivity, and stability, simultaneously, when the Pt loading is 0.05 wt%. However, the presence of excessive Co decreased the activity and selectivity when the Pt loading is 0.5 wt%. For ethylene ADeH, we show that the Re/HZSM-5 catalyst is significantly more active than the Zn, Co, In, Ga, and Cu modified HZSM-5 catalysts. The selectivity and space-time-yield of acetonitrile are up to 80% and 1300 μmol/g/min, respectively, over the optimized Re/HZSM-5 (SiO 2 /Al 2 O 3 = 80) catalyst. We suggested that an appropriate balance between the metal functionality (for dehydrogenation) and acid density (for amination) be critical for both ethane and ethylene ADeH. • Acetonitrile can be produced through co-processing ethane or ethylene with NH 3 under anaerobic conditions • The presence of Co tunes the catalytic behavior of the benchmark Pt/HZSM-5 during ethane ammodehydrogenation • Ethylene ammodehydrogenation can be realized over Re/HZSM-5 • An appropriate balance between the metal and acid functionalities is critical for both ethane and ethylene ammodehydrogenation