The introduction of an appropriate amount of Cu effectively enhances the catalytic performance of ZnO-ZrO2 solid solution catalysts in CO2 hydrogenation to methanol. However, systematic studies on the effect of Cu content in ZnO-ZrO2 solid solution catalysts remain limited. In this work, a ZnO-ZrO2 solid solution and a series of Cu/ZnO/ZrO2-x catalysts (x = 0.3, 0.7 and 0.9, denoting the molar ratio of Cu/(Cu+Zn+Zr)) were prepared by co-precipitation method. Among these catalysts, the Cu/ZnO/ZrO2-0.7 catalyst exhibited the optimal catalytic performance, with a space-time yield of methanol (162.7 g/(kg·h)) that was 6.6 times higher than that of the ZnO-ZrO2 solid solution catalyst (24.8 g/(kg·h)) at 250 °C. Structural characterizations reveal that the introduction of an appropriate amount of Cu led to the coexistence of a solid solution and individual metal oxides, and promoted the formation of medium-strength basic sites. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) results further confirm that Cu introduction facilitated the conversion of key reaction intermediates. This work provides a systematic investigation of the influence of Cu content on the methanol synthesis performance of ZnO-ZrO2 solid solution catalysts and elucidates the promotional mechanism induced by Cu incorporation.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |