Enhanced Ammonia Synthesis via Plasma-Assisted Catalysis: Insights Into CoNi Bimetallic Systems on SBA-15 Supports

Nonthermal plasma (NTP)-assisted ammonia synthesis is an emerging catalytic method using plasma technology to activate reactants. It can operate at room temperature and atmospheric pressure, significantly boosting reaction activity and improving ammonia synthesis efficiency. However, standalone plasma systems still face limitations ammonia yield and energy efficiency, highlighting the need for synergistic effects from efficient catalysts to improve overall performance. In this study, a CoNi bimetallic catalyst supported on SBA-15 was designed and synthesized to optimize metal dispersion, increase the exposure of active surface sites, and enhance plasma activation efficiency. SBA-15 was synthesized hydrothermally, and Co and Ni were loaded by impregnation to obtain high-performance catalysts. Under room temperature and atmospheric pressure, the plasma-assisted ammonia synthesis achieved a yield of 228 μmol/(min·g_-cat). Comprehensive structural and surface characterizations (SEM, TEM, XRD, BET, NH₃-TPD, and XPS) revealed that the incorporation of Co significantly improved the dispersion of Ni, reduced the metal particle size, and strengthened the interaction between the metal and the support. These improvements contributed to enhanced adsorption and activation of reactive intermediates. This work provides insights into the design of efficient bimetallic catalysts for plasma-assisted ammonia synthesis and contributes to sustainable nitrogen utilization within the framework of a circular nitrogen economy.