Ruthenium based with carbon supported catalysts for the catalytic transfer hydrogenation of furfural: A review

Due to its deterrence of high-pressure fossil-derived H2 and possible reduction in process costs, catalytic transfer hydrogenation (CTH) has subsequently risen to prominence as a very appealing method for biomass-based hydrogenation. The CTH of furfural (FF) involves the reduction of carbonyl group to a hydroxyl group using a hydrogen donor in the presence of carbon based catalyst. In this process, catalyst plays a crucial role in promoting the hydrogenation reaction and enhancing selectivity towards the desired product. Ruthenium (Ru) is a highly active catalyst for CTH reactions due to its unique electronic properties and ability to activate molecular hydrogen. Carbon-supported Ru catalysts are preferred over unsupported Ru catalysts because they offer higher stability, improved activity, and better selectivity. In this focused review, we selected all recent research papers published on FF hydrogenation over Ru-carbon supported, such as CNTs, GO, rGO, HSAG, HCS, AC and OBC catalysts, which are comprehensively precise. As few studies relating to CTH of FF to cyclopentanone, bio-oils, 2-MF, and FFA over Ru carbon supported catalysts have been described in recent research studies, it is quite urgent to focus review on the latest progress. We have focused on bridging the knowledge gap between the fundamental insights gained from single or multimetallic systems of the noble metal Ru. This review paper presents a comprehensive evaluation of experimental studies that focus on FF hydrogenation with Ru-based carbon supported catalysts into value-added chemicals and fuels. It also analyzes the impact of reaction conditions such as temperature, hydrogen pressure, stirring speed, and reaction duration. Other prospective research directions might lead to the creation of more efficient catalysts and successful commercialization of CTH method for producing FF hydrogenation in the industrial sector. Finally, this review aims to suggest that future research should focus on discovering Ru based with more efficient carbon-supported catalysts and optimizing FF hydrogenation process to produce high-value chemicals and fuels to improve catalytic performance and selectivity with minimum environmental impact and cost.