Screening of single and binary catalysts for oxidative coupling of methane to value-added chemicals

Effect of surface treatment technique on properties and performance of Na2WO4‐TiO2‐MnOx/SiO2 for oxidative coupling of methane

“…For NWTM‐CC, the activity slightly decreased from the fifth to the eighteenth hour and then remained virtually unchanged. The slow deactivation of NWTM‐CC, as has been reported previously, was primarily because of the sintering and agglomeration of active particles 69 . NWTM‐EB showed the most rapid decrease in C 2+ activity from the fourth to the seventh hour and maintained the low C 2+ activity for the rest of the testing period.…”

“…1(b)). 69 NWTM‐WT and NWTM‐CP showed a slow decrease in activity that was mainly affected by the change to the crystalline phases of the active components in the catalysts, as previously shown in the XRD results in Fig. 1.…”

“…This suggests that this catalyst is excellent at sustaining its structure under harsh conditions. After the fifteenth hour, a slow decrease in C 2+ activity was observed due to the sintering and agglomeration of the active component to lager particles, as well as the destructuring 69 NWTM-WT and NWTM-CP showed a slow decrease in activity that was mainly affected by the change to the crystalline phases of the active components in the catalysts, as previously shown in the XRD results in Fig. 1.…”

“…The slow deactivation of NWTM-CC, as has been reported previously, was primarily because of the sintering and agglomeration of active particles. 69 NWTM-EB showed the most rapid decrease in C 2+ activity from the fourth to the seventh hour and maintained the low C 2+ activity for the rest of the testing period. According to the elemental quantification results in Table 3 and the fresh and used XRD patterns of NWTM-EB, there were no active elements (especially for W and Ti) on the fresh NWTM-EB catalyst's surface and there were relatively low intensities of the active components.…”

Effect of thermal treatment on the stability of Na–Mn–W/SiO2 catalyst for the oxidative coupling of methane

“…Multiple catalyst formulations have been tested for the OCM reaction, including alkaline oxides, rare earth metal oxides and transition metal oxides 6,7,[11][12][13][14] . Among them, the Na-Mn-W/SiO 2 is generally accepted to be one of the most promising catalyst materials showing high catalytic performance (> 20 % yield) and long-term stability [15][16][17] .…”