Effects of Nb Promoter on the Properties of Cu/ZnO/SBA-15 Catalyst and Performance in Methanol Production

Abstract

Hydrogenation of CO2 provides an alternative route for methanol production and attractive option for CO2 utilization. The present work investigates the synthesis of Cu-based catalyst on mesoporous silica (SBA-15) and promotion of the Cu-based catalyst with niobium (Nb). The addition of Nb promoter enhanced the reducibility and dispersion of the active sites as well as increased the BET and Cu surface areas. The performance of the synthesized catalyst in the hydrogenation of CO2 was evaluated in a fixed-bed microreactor at 523K, 22.5bar and H2/CO2 of 3. The CO2 conversion using the Cu/ZnO/SBA-15 catalyst was 14.2 % and increased to 17.1% on the Nb-promoted catalyst. The yield of methanol obtained using the un-promoted Cu-based catalyst was 51.4 g/h.gcat and it increased to 143 g/h.gcat over the Nb-promoted catalyst.

Effect of the Synthesis Method on Physicochemical Properties and Performance of Cu/ZnO/Nb2O5 Catalysts for CO2 Hydrogenation to Methanol

“…17 In this direction, Zabidi et al studied the CO 2 hydrogenation reaction on Cu/ZnO/SBA-15 promoted with 1 wt % Nb. 7 They observed that Nb led to increased dispersion and metallic area of Cu and favored the reducibility of the material. As a result of these modifications, the CO 2 conversion and methanol production were optimized.…”

“…As a result of these modifications, the CO 2 conversion and methanol production were optimized. 7 In contrast, considering the strategy of exploring different synthesis methodologies, Liu et al evaluated the deposition− precipitation, coprecipitation, and impregnation methods to prepare Cu/ZrO 2 catalysts. 9 The Cu/ZrO 2 synthesized by the deposition−precipitation method presented a more uniform particle size distribution, smaller particles, and a larger specific surface area than those prepared by coprecipitation or impregnation methods.…”

“…In these processes, a wide variety of value-added chemicals can be obtained. − In particular, methanol is an interesting product of catalytic CO 2 hydrogenation, owing to its broad range of applications. Previous studies showed that Cu/ZnO-based materials are promising for large-scale methanol production from CO 2 and H 2 . , The properties of these materials can be modulated using promoters , and applying different synthesis methods. , Promoters, such as Fe, Ga, , Mg, Al, and In, can increase the dispersion of Cu, maximizing interface sites and the basicity, raising the CO 2 adsorption, while the synthesis method influences the morphology and structure of the catalysts, − allowing the optimization of the methanol generation.…”

“…Among the elements previously investigated as promoters, Lopes et al showed that niobium oxides increase the activity of the material and prolong the catalyst lifetime when added in small amounts . In this direction, Zabidi et al studied the CO 2 hydrogenation reaction on Cu/ZnO/SBA-15 promoted with 1 wt % Nb . They observed that Nb led to increased dispersion and metallic area of Cu and favored the reducibility of the material.…”

“…They observed that Nb led to increased dispersion and metallic area of Cu and favored the reducibility of the material. As a result of these modifications, the CO 2 conversion and methanol production were optimized . In contrast, considering the strategy of exploring different synthesis methodologies, Liu et al evaluated the deposition–precipitation, coprecipitation, and impregnation methods to prepare Cu/ZrO 2 catalysts .…”