CoP nanowires on carbon cloth for electrocatalytic NOx- reduction to ammonia

Electrocatalysis provides a promising green solution to replace the industrial Haber-Bosch process for ammonia production under ambient conditions. The indirect method for ammonia synthesis (N-2 -> NOx -> NH3) have recently received great attention and development of efficient catalysts for selective NOx conversion to NH3 is of key importance. Herein, we report the preparation of uniform CoP nanwire arrays self-supported on carbon cloth as efficient catalyst for electrocatalytic nitrite (NO2-) and nitrate (NO3-) reduction to synthesize ammonia in alkaline NaOH solution. The material demonstrated efficient ammonia generation rate of 380 mu g*h(-1)*cm(-2)for NO2- reduction and a faradic efficiency of 91.6% obtained at -0.3 V vs RHE, and 317 mu g*h(-1)*cm(-2) for NO3- reduction and a faradic efficiency of 65% at -0.4 V vs RHE. More importantly, the CoP catalyst displayed robust stability and maintained its activity even after 10 cycles of elctrocatalysis. This work demonstrated the great potential of carbon cloth supported metal phosphides for efficient ammonia production through electrocatalytic NOx conversion.