Cellulose‐Phytic Acid Composite Complexed Ru Catalyst for CO2 Hydrogenation to Free Formic Acid

Abstract The CO 2 hydrogenation to free formic acid is an interesting topic, and low‐cost and high‐performance catalysts are highly desirable. This work presents a simple and green strategy to prepare high‐performance Ru catalysts for CO 2 hydrogenation using cellulose and phytic acid composite (CPC) as support to complex with Ru(III). The CPC support prepared with assistance of 1‐butyl‐3‐methyl imidazolium chloride exhibits porous structure with abundant free −OH and −PO 4 groups that can complex with Ru(III). The CPC complexed Ru catalyst (e. g., CPC‐Ru‐1) showed much higher activity for CO 2 hydrogenation to formic acid in 1‐butyl‐3‐methyl imidazolium acetate than the reported heterogeneous Ru catalysts. Especially, CPC‐Ru‐1 with 0.094 wt% Ru afforded formic acid in selectivity >99 % with a turnover number around 1.8×10 4 and an initial production rate of 15.21 mol ⋅ g −1 ⋅ h −1 within the first 2 h at 120 °C. This catalyst is recyclable and stable without obvious activity loss after 5 runs.