Fundamentals and Advances in Emerging Crystalline Porous Materials for Photocatalytic and Electrocatalytic Nitrogen Fixation

Artificial nitrogen fixation, which uses N2 and H2O as raw materials and is powered by renewable energy, is a more environmentally friendly method of permitting NH3 synthesis under ambient conditions than the industrial Haber–Bosch process. However, only a few catalysts have been reported that can efficiently reduce the nitrogen activation barrier, resulting in low NH3 production efficiency. Emerging crystalline porous materials (CPMs) are a class of lightweight porous network materials composed of metal and organic linking units through coordinate bonds or organic structural units through covalent bonds, with high surface areas, tunable pores, and designable compositions and structures. CPMs offer intriguing applications as catalysts for photocatalytic and electrocatalytic nitrogen fixation reactions due to their unique structures and characteristics, and significant progress has been made. This Review systematically summarizes the synthetic methods of emerging CPMs (MOFs and COFs), basic principles of photocatalytic and electrocatalytic nitrogen fixation reactions, some representative NH3 synthesis catalysts and modification strategies, and common reactor types. Finally, prospective development directions of photocatalytic and electrocatalytic nitrogen fixation based on CPMs are proposed, providing a research basis for accelerating the industrialization of artificial nitrogen fixation driven by renewable energy.