Investigating the effect of active metal percentage composition on catalyticperformance in the oxidative coupling reaction of methane

The Oxidative Coupling of Methane (OCM) reaction [۱] holds significant potential for theproduction of valuable products from methane. However, it is confronted with several challenges,including low selectivity towards the desired products and high energy requirements for thereaction conditions. As a result, ongoing research efforts are focused on developing more effectivecatalysts and optimizing reaction conditions to enhance the selectivity and efficiency of the OCMprocess [۲-۴]. In this investigation, we synthesized three distinct variants of Mn-Na۲WO۴/SiO۲catalysts, employing different compositions ranging from ۴% to ۶%. The catalytic performance ofthese catalysts, designated as A, B, and C, was initially evaluated for the oxidative coupling ofmethane (OCM). The experimental conditions included a total flow rate of ۴۸۰ mL/min, withmethane-to-oxygen ratios of ۲ and ۴. Among the catalysts tested, catalyst A exhibited remarkableefficacy in generating C۲H۴ and C۲H۶ products compared to catalysts B and C. To furthercharacterize the catalytic behavior, methane conversion and selectivity towards C۲ hydrocarbonswere determined for catalysts A, B, and C at three distinct temperatures: ۸۰۰, ۸۲۵, and ۸۵۰ °C.Notably, the desired catalysts displayed enhanced performance at elevated temperatures.Additionally, the highest conversion of reactants was achieved when the methane-to-oxygen feedratio was set to ۲, specifically at a temperature of ۸۰۰ °C. To evaluate the properties of thesynthesized catalyst, various characterization techniques such as X-ray diffraction (XRD), Fouriertransforminfrared spectroscopy (FTIR), temperature-programmed reduction (TPR), Brunauer-Emmett-Teller (BET) surface analysis, and field emission scanning electron microscopy (FESEM)were employed