PdCuZn/SiC catalysts were synthesized with different Pd:Cu:Zn molar compositions and tested in the hydrogenation of carbon dioxide to methanol at atmospheric pressure. Trimetallic catalysts were compared with the corresponding bimetallic ones (PdZn/SiC, CuZn/SiC and PdCu/SiC). Catalysts were characterized by N₂ adsorption/desorption, temperature-programed reduction (TPR), X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The Pd⁰ active sites were related to carbon monoxide formation via reverse water-gas-shift (RWGS), whereas the PdZn alloys catalyzed methanol synthesis. The role of copper in trimetallic catalysts was to inhibit the deposition of metallic palladium by forming a PdCu alloy that proved to be less active to CO formation. Moreover, the active sites of trimetallic catalysts were smaller and better dispersed than those of the corresponding bimetallic ones, probably due to a synergistic effect between the three metals. The catalyst with a molar composition of 37.5:12.5:50 Pd:Cu:Zn (mol.%) was selected as the most active for the methanol synthesis, as this sample showed the highest activity and selectivity to methanol. The role of copper was also shown to be crucial in trimetallic catalyst by comparing the best example with an equivalent bimetallic PdZn/SiC with a Pd:Zn molar ratio of 37.5:62.5.

合成了具有不同Pd：Cu：Zn摩尔组成的PdCuZn / SiC催化剂，并在大气压下将二氧化碳氢化为甲醇的过程中进行了测试。将三金属催化剂与相应的双金属催化剂（PdZn / SiC，CuZn / SiC和PdCu / SiC）进行了比较。催化剂的特征在于N ₂吸附/解吸，程序升温还原（TPR），X射线衍射（XRD），透射电子显微镜（TEM），能量色散X射线光谱（EDS）和X射线光电子光谱（XPS） ）。Pd ⁰活性位与通过反向水煤气变换（RWGS）形成一氧化碳有关，而PdZn合金则催化甲醇的合成。铜在三金属催化剂中的作用是通过形成PdCu合金来抑制金属钯的沉积，事实证明该PdCu合金对CO的形成没有活性。而且，三金属催化剂的活性中心比相应的双金属催化剂的活性中心更小且分散得更好，这可能是由于三种金属之间的协同作用所致。选择摩尔组成为37.5：12.5：50 Pd：Cu：Zn（摩尔％）的催化剂对甲醇合成最具活性，因为该样品显示出最高的活性和对甲醇的选择性。