Enhanced CO₂ Hydrogenation to Methanol on the Mesostructured Cu–ZnO/Al₂O₃–ZrO₂ Catalyst

Abstract

In order to obtain high catalytic performance of CO 2 hydrogenation to methanol, mesostructured Cu−ZnO/Al 2 O 3 −ZrO 2 (CZAZ) catalysts were prepared, and the microstructure and surface properties were optimized by the weight ratio of Al 2 O 3 and ZrO 2 . Due to the uniform mesoporous structure and strong interaction of Cu with the support, the mesostructured CZAZ-8 catalyst (Al 2 O 3 weight amount in Al 2 O 3 −ZrO 2 was 80%) had a higher active surface area of metallic Cu and more interfaces of Cu and CO 2 adsorption sites, which promoted the CO 2 conversion. In addition, ZrO 2 added to supports endowed the catalysts with a strong basic surface, and the smaller Cu particles increased the interfaces of Cu with ZnO, which increased the selectivity to methanol. Finally, the catalyst CZAZ-8 with a wellordered mesostructure exhibited a higher space time yield of methanol in the CO 2 hydrogenation.

Photo-assisted effective and selective reduction of CO2to methanol on a Cu–ZnO–ZrO2catalyst

“…1b and c) show that the homogeneous nanoparticles and Cu–ZnO–ZrO 2 have a smaller particle size than Cu–ZnO because of the good dispersion-effect of ZrO 2 . 25,27 The ZnO (0.280 nm), ZrO 2 (0.297 nm), and ambiguous Cu (0.239 nm) lattice spacings can be discerned from Fig. 1d and e.…”

“…Table 1 displays that the particle size of ZnO decreases from 28.0 nm to 21.1 nm after compositing the ternary Cu-ZnO-ZrO 2 catalyst, which indicates that the crystallization of ZnO is inhibited by the addition of ZrO 2 . 24,25 The Cu diffraction peaks could not be observed in Fig. 1a due to the lower Cu percentage (1%).…”

Applications of Al2O3‐Based Nano‐Catalysts in Thermocatalytic CO2 Transformations: Impacts of Surface Acidity and Basicity

“…Based on the literatures, ZnO was able to contribute to a moderate basicity due to the Zn−O pair at Cu−ZnO interface [129,195] . As a result, Cu sites were responsible for the reduced basicity and smaller number of basic sites since some basic sites were occupied by Cu and fewer coordinatively unsaturated O 2− ions were present because of the lower net electronic charge [195–198] . To further modify the surface basicity of Cu/ZnO/Al 2 O 3 , the in‐situ formed layered double hydroxides (LDHs) with Al 2 O 3 as both the Al 3+ source and support acted as a precursor, contributing to more medium and strong basic sites after calcination and reduction compared with Al 2 O 3 with only weak basicity [198–200] .…”

Rational Design and Synthesis of 3D Nanoreactors for Green Fuel Production: Design Band Gap Y@DS Photocatalyst under Visible Irradiation

“…Recently, a large amount of research has been carried out on photocatalytic CO 2 reduction, demonstrating the importance of this subject. − As a result of the hydrogenation process of CO 2 to methanol with the optimized surface properties of Cu–ZnO/Al 2 O 3 –ZrO 2 (CZAZ) catalysts, the catalytic performance of CZAZ catalysts with a mesostructure was evaluated. At 513 K and 5 MPa, 8.7 mmol·gcat –1 ·h –1 methanol (STY MeOH ) was obtained over CZAZ . The photocatalytic activity of CO 2 reduction by SnS/(CH 3 NH 3 ) 2 AgBiI 6 (SCABI) has shown that the charge transfer in SCABI follows the Z-scheme band alignment, conducive to the separation of photoexcited electrons and holes, and that electrons accumulating on the CB of the SnS monolayer have the ability to reduce CO 2 .…”

“…At 513 K and 5 MPa, 8.7 mmol•gcat −1 •h −1 methanol (STY MeOH ) was obtained over CZAZ. 47 The photocatalytic activity of CO 2 reduction by SnS/(CH 3 NH 3 ) 2 AgBiI 6 (SCABI) has shown that the charge transfer in SCABI follows the Z-scheme band alignment, conducive to the separation of photoexcited electrons and holes, and that electrons accumulating on the CB of the SnS monolayer have the ability to reduce CO 2 . Based on the obtained results, the Z-scheme of the SCABI heterostructure proves to be a promising photocatalyst for CO 2 reduction.…”