2963 Introduction Allylic alcohols are highly demanding in pharmaceutical and fine chemical industries. They are extensively used as building blocks/raw materials in the synthesis of value added products like drugs, food additives, fragrances, perfumes, cosmetics, etc. 1–6 . Allylic alcohols can be obtained by selec- tive semi-hydrogenation of , -unsaturated aldehydes. Thus, reduction of ,-unsaturated aldehydes is very valuable from academic as well as industrial point of view. Selective hydro- genation at the olefinic double bond leads to the saturated aldehyde, whereas selective reduction of the aldehydic group leads to the allylic alcohol. Thermodynamics favours the hy- drogenation at the C=C function over the aldehydic group 1 . In spite of that, the total selectivity towards saturated alde- hyde is not easy to achieve because always there is some chance of hydrogenation of the aldehydic function. On the other hand, high selectivity towards allylic alcohol, being ther- modynamically unfavourable, is very difficult to achieve. Hence, selective reduction of the aldehydic group in ,- unsaturated aldehydes to achieve improved yield of allylic alcohol is very important and demanding. Heterogeneous catalytic hydrogenation is environmentally friendlier process because it produces less amount of waste; also, the catalyst CSD-2019 Special Issue J. Indian Chem. Soc., Vol. 97, No. 12c, December 2020, pp. 2963-2966 Promotion of carbon xerogel supported Pt catalyst by Co and Zn for liquid phase hydrogenation of cinnamaldehyde Kamala Mandy Hansda, Ajit Das, Anupama Mahato, Purnima Singh and Nagendranath Mahata* Center for Adsorption and Reaction Engineering on Surface (CARES), Department of Chemistry, Sidho-Kanho-Birsha University, Purulia-723 104, West Bengal, India E- mail: nagendranath_mahata.chem@skbu.ac.in Manuscript received online 04 December 2020, accepted 24 December 2020 Pt catalysts, supported on mesoporous carbon xerogel and promoted by Co and Zn, were prepared following impregnation method. The catalysts were assessed in liquid phase hydrogenation of cinnamaldehyde. Characterisation of the catalysts was done by elemental analysis, N 2 adsorption, H 2 pulse chemisorptions and X-ray photoelectron spectroscopy. The promoters, Co and Zn, were found to improve the cinnamaldehyde hydrogenation activity of Pt remarkably. The promoters also greatly increased cinnamyl alcohol selectivity. When both the promoters were applied together a further augmentation of cinnamyl alcohol selectivity was observed. XPS analysis revealed electron transfer from the promoters to Pt. Keywords: Cinnamaldehyde, hydrogenation, Pt catalyst, impregnation, cinnamyl alcohol. can be separated easily from the reaction mixture and may be reused. The importance of heterogeneous catalytic hy- drogenation of ,-unsaturated aldehydes is indeed reflected in number of studies reported in the available literature 1–9 . Cinnamaldehyde (CMD) is an ,-unsaturated aldehyde; it is frequently used as model substrate. The selective semi- hydrogenation at aldehydic group results in cinnamyl alco- hol (CML), a value added outcome useful in fine chemical industry 1,2 . On the other hand, the selective semi-hydroge- nation at C=C function results in hydrocinnamaldehyde (HCMD). HCMD is used in the synthesis of a drug that is useful in the treatment of HIV 4,5 . In addition, both CML and HCMD are used as intermediate in number of organic syn- thesis 1,6 . The complete hydrogenation results in 3-phenyl-1- propanol (PPL). Supported group VIII metal catalysts exhibit excellent hydrogenation activity. There is room for manipula- tion of product selectivity by means of application of suitable promoter 2,10–12 . In the present study, Pt based catalysts were prepared using carbon xerogel as support. Co and Zn were applied as promoters. The catalysts were characterised and assessed in the selective hydrogenation of CMD to CML.