ABSTRACT:
Catalytic methane decomposition is considered as a promising hydrogen production technology without CO₂ emission. Catalyst is generally required to reduce reaction temperature, among which, carbon-based catalysts are widely studied due to their excellent catalytic performance and low cost. Activated carbon (AC), although presents high initial activity, suffers from fast deactivation; In comparison, carbon black (CB) shows low activity but good stability, and its catalytic performance maintains ability inspires a novel method for AC optimization. According to the physical property difference of AC and CB, a novel catalyst is prepared by doping CB on the surface and in the pores of AC. And surface property modified by HNO3 is also recommended, because the increase of functional groups further improves the adsorption performance. The results illustrate that AC_N+BP2000-20:3 show advantages in hydrogen yield, weight increase velocity and carbon yield. Meanwhile, not only the initial activity is improved by a large margin, but also the deactivation time is progressively prolonged. The analysis results show that CB loading significantly increased the number of micropores, which is the key factor for the high initial catalytic activity. And the protrusion, induced by CB, are characterized by unique graphene edges defect, which provides active sites and furtherly promotes the reaction.
 

Catalytic methane decomposition; Activated carbon; Carbon black; HNO3 modification; Defect structure