This work reports the performance of low metal loading (about 3 wt.%) Rh, Ni and Mo-Ni catalysts supported on carbon in the hydrodeoxygenation (HDO) of phenol. The catalytic tests were carried out in a flow microreactor at 310 °C and at a total hydrogen pressure of 3 MPa. A commercial NiMoP/γ-Al₂O₃ sulfided catalyst was used as reference. The effect of catalyst pre-treatment (reduction against sulfidation) was investigated in the case of the noble metal catalyst. The thermally treated in inert atmosphere, fresh reduced and spent catalysts have been characterized by several physicochemical techniques: chemical analysis, N₂ adsorption-desorption isotherms, Raman spectroscopy, Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and High Resolution Transmission Electron Microscopy (HRTEM).

The HDO of phenol was found to be favored on the bifunctional Rh/C and Ni/AC catalysts which exhibit a large amount of well dispersed metallic species (from HRTEM). Contrary to a commercial sulfided NiMo/Al₂O₃ catalyst, the hydrogenation of aromatic ring of phenol was favored being the CO bond hydrogenolysis a minor reaction route. Catalytic HDO of phenol over Rh/C reveal that the catalyst activation by reduction is advantageous compared to that by sulfidation. The partial substitution of Ni by Mo in the Mo-Ni/AC catalyst led to enhance of the catalyst stability but decrease of overall activity occurs due to the decrease of amount of metallic nickel species. The role of the MoO₃ species in the inhibition of deactivation by coke is discussed.

这项工作报告了在苯酚的加氢脱氧（HDO）中负载在碳上的低金属负载量（约3 wt。％）Rh，Ni和Mo-Ni催化剂的性能。在流动微型反应器中在310°C和3 MPa的总氢气压力下进行了催化测试。一种商业NiMoP /γ-Al系₂ ö ₃硫化的催化剂被用作参考。在贵金属催化剂的情况下，研究了催化剂预处理的效果（减少了硫化作用）。在惰性气氛中进行了热处理，新鲜的还原催化剂和废催化剂已通过几种物理化学技术进行了表征：化学分析，N ₂吸附-解吸等温线，拉曼光谱，扫描电子显微镜（SEM），X射线衍射（XRD），X射线光电子光谱（XPS）和高分辨率透射电子显微镜（HRTEM）。

苯酚的HDO被发现在双官能的Rh / C和Ni / AC催化剂上更受欢迎，这些催化剂表现出大量分散良好的金属物质（来自HRTEM）。与商业硫化的NiMo / Al ₂ O ₃催化剂相反，苯酚的芳环的氢化被认为是CO键氢解的次要反应途径。苯酚在Rh / C上的催化HDO结果表明，与硫化相比，还原反应对催化剂的活化作用更为有利。Mo-Ni / AC催化剂中的Mo部分取代Ni导致催化剂稳定性的增强，但是由于金属镍种类的减少导致整体活性降低。讨论了MoO ₃物种在抑制焦炭失活中的作用。