ZSM-۵ based nanocomposites for photocatalytic production of ammonia

Environmental problems including climate change, global warming, and environmental pollutants along with the heavy dependence of modern human life on various sources of energy and agricultural, pharmaceutical, and petrochemical industries have caused significant concerns in the present century [۱, ۲]. Ammonia (NH۳), as a raw material, plays an essential role in development of agricultural and modern industrial products. Therefore, the production of ammonia is an urgent need for the development of various industries. In recent years, photocatalyst-based processes have emerged highly promising for the conversion of N۲ to NH۳. The photofixation of N۲ to NH۳ has several advantages such as low energy consumption and minimal environmental pollution. The reaction it is carried out under ambient pressure and temperature, and the CO۲ emission is negligible [۲, ۳]. Recently, we have synthesized composites of nano semiconductors (including zinc ferrite, titanium dioxide/zinc ferrite, cobalt ferrite, cobalt oxide/GQD, and zinc oxide/GO) with different ZSM-۵ type metalosilicates and investigated their performance in the photocatalytic production of ammonia. ZSM-۵ type metalosilicates are microporous materials in which SiO۴ and MO۴ (M= Fe, Cr, Co, Al, etc.) tetrahedra link together via bridging O atoms. The high surface area and unique porous structure of ZSM-۵ type metalosilicates help the uniform dispersion of nanoparticles on zeolite surface. As a result, the agglomeration of nanoparticles, which contributes to reducing the active sites of photocatalyst, is decreased [۴-۶]. In this regard, the prepared nano semiconductor/ZSM-۵ type metalosilicate composites showed a higher rate of ammonia production in comparison to pure nano semiconductors. The amount of produced ammonia in this research was also higher than the values reported in the other literature.

کلیدواژه ها:

ZSM-۵ ، Metalosilicate ، Nanosemiconductor ، Composite ، Ammonia