Catalytic Light Alkanes Conversion Through Anaerobic Ammodehydrogenation

Catalytic transformation of light alkanes could have considerable practical value, yet remains one of the most challenging areas in catalysis research due to the inertness of the C-H bond. Here, we proposed an efficient ammodehydrogenation (ADeH) catalytic system for the direct C-N linkage between light alkanes and ammonia for CH3CN and H-2(COx free) production. This breakthrough is achieved over bifunctional metal-modified HZSM-S catalysts, through the tandem dehydrogenation-amination-dehydrogenation mechanism. We show that ethane ADeH over the Pt/HZSM-5 catalyst can be realized under atmospheric pressure at temperatures as low as 350 degrees C. The specific rate of CH3CN is similar to 60 mu mol/(g min), and the selectivity is up to 99% under such mild conditions. The yield of CH3CN increases with increasing temperature; however, the selectivity decreases due to the formation of HCN, C2H4, and CH4. Additionally, the Pt/HZSM-S catalyst is coke-resistant during the ADeH owing to the strong interaction between NH3 and the acid sites of the catalyst. We anticipate that the proposed ADeH could be extended for the transformation of various n/iso-alkanes with tunable selectivity to alkene and nitriles.