Single Solid Precursor-Derived Three-Dimensional Nanowire Networks of CuZn-Silicate for CO2 Hydrogenation to Methanol

Hydrogenation of CO2 to MeOH is one of the most promising technologies in mitigating the emissions of CO2 and tackling the challenge of climate change. In this work, we present a synthetic protocol for preparing a Cu–ZnO-based heterogeneous catalyst supported by siliceous nanowire networks from a single solid precursor with a tunable composition. The resulting Si–Cu–Zn catalysts were evaluated with the MeOH synthesis from the CO2 hydrogenation reaction operated at moderate conditions (30 barg and 200–280 °C). A specific MeOH yield of 402 mgMeOH·gCu–1·h–1 and a MeOH selectivity of 51% were obtained at 240 °C. Such a performance was attributed to several structural and compositional merits, granted through the attentively engineered synthetic procedures. Small Cu nanoparticle (NP) size was achieved and maintained by the high dispersion of Cu to the atomic level in the precatalyst and the incorporation of ZnO as a structural promoter. Moreover, the desirable Cu–ZnO synergistic effect can be further attained from the strong metal–support interaction (SMSI) between the Cu NPs and the partially reduced ZnO phase. Lastly, the robust siliceous nanowire networks provided decent spatial confinement to contain the growth of Cu NPs while offering high accessibility with the macroscopic porous morphology. The catalyst exhibited stable performance over a week’s long stability test while keeping its structural integrity intact. Overall, this study may offer an alternative design and synthesis strategy for the well-received Cu–ZnO system to approach its high performance in CO2 hydrogenation.