[EN] Technological approaches which enable the effective utilization of CO for manufacturing value-added chemicals and fuels can help to solve environmental problems derived from large CO emissions associated with the use of fossil fuels. One of the most interesting products that can be synthesized from CO is methanol, since it is an industrial commodity used in several chemical products and also an efficient transportation fuel. In this review, we highlight the recent advances in the development of heterogeneous catalysts and processes for the direct hydrogenation of CO to methanol. The main efforts focused on the improvement of conventional Cu/ZnO based catalysts and the development of new catalytic systems targeting the specific needs for CO to methanol reactions (unfavourable thermodynamics, production of high amount of water and high methanol selectivity under high or full CO conversion). Major studies on the development of active and selective catalysts based on thermodynamics, mechanisms, nano-synthesis and catalyst design (active phase, promoters, supports, etc.) are highlighted in this review. Finally, a summary concerning future perspectives on the research and development of efficient heterogeneous catalysts for methanol synthesis from CO will be presented., The present investigation was funded by the research project CTQ2016-76505-C3-1 supported by the Spanish Ministry of Science, Innovation and Universities and the program BIOTRES-CM (S2018/EMT-4344) supported by the Comunidad Autónoma de Madrid. Elena Millán would like to acknowledge the FPI programme from Spanish Ministry of Science, Innovation and Universities for the research grant.

This contribution describes the modification in the structure and activity of Cu/ZnO catalyst in the methanol synthesis reaction induced by the co-modification with a low amount of Al and Ga (Al+Ga=3% atom). To elucidate the effect of the co modification, the catalysts were characterized by means of variety of techniques (XRD, N2 physisorption, FTIR, TGA, TEM, TPR and N2O chemisorption) and tested in the methanol synthesis
reaction carried out in a flow reactor at 250 °C and total pressure of 3 MPa using syngas. The combined characterization and activity tests demonstrated that the co-doping with Al and Ga affects the structure and activity of Cu/ZnO catalysts in a different manner depending on the Al/Ga ratio used. The best catalyst co-loaded with Ga and Al in equal amount shows an improvement in the activity for methanol synthesis respect to the activity obtained on catalysts individually loaded with Al and Ga. The difference in the activity of the samples co-loaded with Al and Ga normalized by N2O chemisorption point to a different participation of the copper surfaces in combination with the defect sites of ZnO depending on the Al and Ga loading., The present investigation was performed within the research program CTQ2016-76505-C3-1 supported by the Spanish Ministry of Science, Innovation and Universities. Elena Millán would like to acknowledge the FPI programme from Spanish Ministry of Science, Innovation and Universities for the research grant.