<p>A set of catalysts with different manganese content on alumina support were prepared and characterized by various spectroscopic techniques. These catalysts were evaluated for continuous vapor phase cross-ketonization of benzoic acid with cyclohexane carboxylic acid to synthesize cyclohexyl phenyl ketone. The catalysts characteristic results indicated the presence of different manganese oxide forms.&#xa0;The activity influenced by the manganese oxide phases and the formation of these phases depended on the content of manganese oxide in the catalyst.&#xa0;The catalysts with high amount of Mn₃O₄ phase showed better conversion of benzoic acid with selective formation of cyclohexyl phenyl ketone. The ketonization reaction was tested under different reaction conditions and optimized reaction parameters were established. The catalyst showed high stability during the time on stream analysis.</p> Graphical abstract <p> The preparation of cyclohexyl phenyl ketone was achieved through a continuous vapour phase cross-ketonization reaction of benzoic acid with cyclohexane carboxylic acid over Mn oxide supported on Al₂O₃ catalyst. Mn₂O₃ and Mn₃O₄ phases are highly active for ketonization. The catalysts are highly stable and selective during time on stream analysis.</p>