Rh/MnO₂-CeO₂/Al₂O₃ catalysts with different manganese-to-ceria ratios have been synthesized, characterized and tested in CO-PrOx reaction. The physicochemical properties of the solids were studied by XRD, Raman spectroscopy, BET surface area, H₂-TPR, TGA-DTG and TEM. The differences observed in the textural, structural and redox properties were related to the Mn-to-ceria ratio of the samples. The segregation of Mn species was observed at high Mn-to-Ce ratios. In opposite way, MnO₂-CeO₂ solid solutions were obtained at low Mn to Ce ones. In this last case, the physicochemical properties of the solids were favored by the intimate Rh-Ce-Mn contact. The effect of the Mn-Ce presence on Rh catalysts which promotes the catalytic behavior towards selective CO oxidation was observed to be better at low temperatures. At higher temperatures, Mn species promote the Reverse Water Gas Shift reaction, whilst ceria promotes the H₂ oxidation in the whole range of working temperatures.

合成，表征并在CO-PrOx反应中测试了具有不同锰对二氧化铈比例的Rh / MnO ₂ -CeO ₂ / Al ₂ O ₃催化剂。通过XRD，拉曼光谱，BET表面积，H ₂ -TPR，TGA-DTG和TEM研究了固体的理化性质。观察到的结构，结构和氧化还原特性的差异与样品的Mn /铈土比例有关。在高的Mn-Ce比下观察到Mn的偏析。相反，MnO ₂ -CeO ₂在低Mn至Ce下获得固溶体。在后一种情况下，紧密的Rh-Ce-Mn接触有利于固体的物理化学性质。在低温下，观察到Mn-Ce的存在对Rh催化剂的促进催化选择性CO氧化的催化行为的效果更好。在较高温度下，Mn物种会促进反向水煤气变换反应，而二氧化铈会在整个工作温度范围内促进H ₂氧化。