Enhancing Green Ammonia Electrosynthesis Through Tuning Sn Vacancies in Sn-Based MXene/MAX Hybrids

Abstract Renewable energy driven N 2 electroreduction with air as nitrogen source holds great promise for realizing scalable green ammonia production. However, relevant out-lab research is still in its infancy. Herein, a novel Sn-based MXene/MAX hybrid with abundant Sn vacancies, Sn@Ti 2 CT X /Ti 2 SnC–V, was synthesized by controlled etching Sn@Ti 2 SnC MAX phase and demonstrated as an efficient electrocatalyst for electrocatalytic N 2 reduction. Due to the synergistic effect of MXene/MAX heterostructure, the existence of Sn vacancies and the highly dispersed Sn active sites, the obtained Sn@Ti 2 CT X /Ti 2 SnC–V exhibits an optimal NH 3 yield of 28.4 µg h −1 mg cat −1 with an excellent FE of 15.57% at − 0.4 V versus reversible hydrogen electrode in 0.1 M Na 2 SO 4 , as well as an ultra-long durability. Noticeably, this catalyst represents a satisfactory NH 3 yield rate of 10.53 µg h −1 mg −1 in the home-made simulation device, where commercial electrochemical photovoltaic cell was employed as power source, air and ultrapure water as feed stock. The as-proposed strategy represents great potential toward ammonia production in terms of financial cost according to the systematic technical economic analysis. This work is of significance for large-scale green ammonia production.