Iron single-atom anchored N-doped carbon: an efficient catalyst for one-pot, scaled-up pentazolate synthesis

Abstract

The discovery of ambient stable pentazolate salts has paved way for a new frontier in the chemistry of pentazoles, which represent a distinctive category of energetic materials. One challenge impeding their practical applications lies in achieving the scale-up of pentazolate synthesis via a facile and low-cost route. An efficient and recyclable iron single-atom catalyst with FeN₄ sites (Fe₁@NC-700) has been first developed using a pyrolysis-milling strategy for scaled-up pentazolate synthesis and achieves significant yields (38.4 g, 15% yield for NaN₅; 77.6 g, 26% yield for CoN₅) via a three-step, one-pot process with a low iron dosage (0.67 mol%). According to experimental and theoretical calculation results, the exceptional catalytic performance of Fe₁@NC-700 can be attributed to its stable FeN₄ enzyme-like catalytic active sites, which facilitate the formation of a Fe(IV)O intermediate, and it maintains its catalytic activity even under weakly acidic conditions and after five cycles.