Featured Application: Catalytic transfer hydrogenation from alcohols allow converting under mild reaction conditions glucose into sorbitol.Abstract: Sorbitol production from glucose was studied through catalytic transfer hydrogenation (CTH) over Raney nickel catalysts in alcohol media, used as solvents and hydrogen donors. It was found that alcohol sugars, sorbitol and mannitol, can be derived from two hydrogen transfer pathways, one produced involving the sacrificing alcohol as a hydrogen donor, and a second one involving glucose disproportionation. Comparison between short-chain alcohols evidenced that ethanol was able to reduce glucose in the presence of Raney nickel under neutral conditions. Side reactions include fructose and mannose production via glucose isomerization, which occur even in the absence of the catalyst. Blank reaction tests allowed evaluating the extension of the isomerization pathway. The influence of several operation parameters, like the temperature or the catalyst loading, as well as the use of metal promoters (Mo and Fe-Cr) over Raney nickel, was examined. This strategy opens new possibilities for the sustainable production of sugar alcohols.Sorbitol production was reported to be carried out using cellulose in the presence of noble metals [9] and transition metal-based catalysts [10,11]. However, a most extended alternative is its production starting from glucose. At an industrial scale, sorbitol is produced via glucose hydrogenation [2] as it is the most affordable precursor [12], whose production is liable to be obtained via cellulose hydrolysis [13,14]. The reaction mechanism consists of the reduction of carbonyl groups of saccharides under hydrogen pressure in the presence of a solid metal catalyst based on Ni, Pd, Pt, or Ru [15,16]. All these catalysts are easily recoverable and display good catalytic activity in terms of sorbitol yield, operating under aqueous-phase solution [6,[17][18][19][20]. In recent years, Raney nickel and ruthenium catalysts made a clean sweep on sorbitol production. Ru presents higher activity and selectivity to sorbitol [16,21] than Raney nickel catalysts, but this metal is much more expensive than nickel-based catalysts. In this way, Raney nickel was revealed as the most interesting active phase to be used in the industrial-scale hydrogenation of glucose [21,22], mostly because of its low price [23]. Nevertheless, the lower catalytic activity of nickel as compared to other precious-metal-based conventional hydrogenation catalysts, such as ruthenium, results in the need for high hydrogen pressure and harsh operating conditions. Consequently, a significant energy demand must be satisfied compared to that required when using more active hydrogenation catalysts and, thus, higher environmental impacts are associated with the use of Raney nickel catalysts [24].This work focuses on gaining insights into a developing alternative reaction pathway to the conventional hydrogenation procedure used to transform glucose into sorbitol by exploring the feasibility of car...