The triggering of catalysis via structural engineering at atomic level:Direct propane dehydrogenation on Fe-N3P-C

The on-purpose direct propane dehydrogenation(PDH)has received extensive attention to meet the ever-increasing demand of propylene.In this work,by means of density functional theory(DFT)calculations,we systematically studied the intrinsic coordinating effect of Fe single-atom catalysts in PDH.Interest-ingly,the N and P dual-coordinated single Fe(Fe-N3P-C)significantly outperform the Fe-N4_C site in catalysis and exhibit desired activity and selectivity at industrial PDH temperatures.The mechanistic ori-gin of different performance on Fe-N3P-C and Fe-N4_C has been ascribed to the geometric effect.To be specific,the in-plane configuration of Fe-N4 site exhibits low H affinity,which results in poor activity in C-H bond activations.By contrast,the out-of-plane structure of Fe-N3P-C site exhibits moderate H affin-ity,which not only promote the C-H bond scission but also offer a platform for obtaining appropriate H diffusion rate which ensures the high selectivity of propylene and the regeneration of catalysts.This work demonstrates promising applications of dual-coordinated single-atom catalysts for highly selective propane dehydrogenation.