Experimental Investigation into Atmospheric Microwave Plasma-Driven Nitrogen Fixation Using Metal-Organic Frameworks

Microwave plasma-driven nitrogen fixation can occur at atmospheric pressure without complex processing conditions. However, this method still faces the challenge of high energy consumption and low production. Combined plasma-catalyst systems are widely used to increase production and reduce energy consumption in nitrogen fixation. However, the efficacy of currently used catalysts remains limited. In this paper, the metal-organic framework materials (MOFs) copper benzene-1,3,5-tricarboxylate (Cu-BTC) and zeolitic imidazolate framework-8 (ZIF-8) are combined with atmospheric microwave plasma for nitrogen fixation. The experimental results show that they have a better catalytic effect than the ordinary catalyst zeolite socony mobil-5 (ZSM-5). The maximum nitrogen oxide concentration reaches 33,400 ppm, and the lowest energy consumption is 2.05 MJ/mol. Compared to no catalyst, the production of nitrogen oxides (NOx) can be increased by 17.1%, and the energy consumption can be reduced by 14.6%. The stability test carried out these catalysts demonstrates that they have a stable performance within one hour. To the knowledge of the authors, this is the first effort to study the synergistic effects of atmospheric microwave plasma and MOFs on nitrogen fixation. This study also introduces a potentially eco-friendly approach to nitrogen fixation, characterized by its low energy consumption and emissions.