In order to examine the capability of AlPO4 to serve as a catalytic support, we analyzed naphthalene hydrogenation over Pd/AlPO4 catalyst in the presence of CO. This process is an effective storage strategy in the organic hydride method that uses low grade hydrogen. Pd/AlPO4 demonstrated high activity in naphthalene hydrogenation similar to Pd/SiO2–Al2O3, and retained the activity in much higher extent in the presence of CO as compared to Pd/Al2O3. The existence of acidic sites on the surface of AlPO4 was confirmed by ammonia adsorption. FT–IR analysis of adsorbed CO after high temperature evacuation revealed that CO desorbed more easily on Pd surface when supported on acidic materials. Detailed analysis of the IR spectra suggested that acidic support decreased the electronic density of Pd and weakened the adsorption bond. Because CO retardation decreased on acidic supports, Pd catalysts demonstrated high activity in the presence of CO. We found that AlPO4 was an effective acidic support for Pd catalyzed hydrogenation.

Dehydrogenation of ethylbenzene (EB) was examined in the presence of CO2, and the effect of CO2 on Fe2O3, Fe–Ce, Fe–K, and Fe–Ce–K oxide catalysts was evaluated. The rate equation was derived in relation to the Langmuir–Hinshelwood mechanism. The rate constant (k) and the relative adsorption coefficient (\( Z_{{{\text{CO}}_{2} }} \)) were obtained, and it was found that addition of K in the catalyst increased both k and \( Z_{{{\text{CO}}_{2} }}.\) We found that CO2 had a strong affinity for the catalyst surface and that the active sites were basic.

The influence of trace oxygen on the catalytic activity of alumina supported Ru in the liquid phase hydrogenation of aromatic hydrocarbons was studied. The catalytic activity of Ru increased remarkably and the reproducibility was improved by removing dissolved oxygen from the reactant mixture and carefully refining the catalyst transfer procedure into the reactor to avoid exposure to air. Trace oxygen affected Ru very severely, but did not affect Rh, Pd, and Pt much. The activity of Ru was lower than those of Rh, Pd, and Pt in the presence of oxygen as reported in the literature; however, it was the highest when oxygen was removed carefully. Measurements of the adsorbed oxygen suggested that the activity seriously decreased when only the part of Ru surface was covered by oxygen. Bimetallic Pt–Ru catalysts demonstrated high activity even in the presence of oxygen.

The liquid phase hydrogenation of naphthalene was performed in the presence of CO over a commercial Ni/SiO2-Al2O3 catalyst. Naphthalene was hydrogenated even in the presence of CO at elevated temperatures, accompanying the hydrogenation of CO. Two activation energy values were obtained for the naphthalene hydrogenation depending on the reaction temperature. FT-IR measurement of the adsorbed CO was also carried out. Hydrogenation of the adsorbed CO created sites active for naphthalene hydrogenation.