For coping with the increasing petroleum crisis, an efficient conversion of syngas (CO + H2) to gasoline-ranged isoparafins has been paid more and more attention. Here, we report a metallic bifunctional catalyst for this conversion, consisting of highly dispersed Ru nanoparticles (NPs) and H-Beta zeolite support, prepared by a self-made polygonal barrel-sputtering process. The HRTEM and chemisorption results indicated that sputterd Ru NPs exhibited a high metal dispersion of 31.2% with a narrow diameter of 2–4 nm. These metallic Ru NPs were bonded with the acidic zeolite by a weakly physical force, clearly different from the conventional impregnated one. Without any reduction pretreatment, the Ru/H-Beta catalyst could be directly used in Fischer–Tropsch synthesis, showing a CO conversion of 1.6 times as much as the impregnated one. Furthermore, the short distance between sputtered Ru and acidic sites nearby was responsible for the enhanced Ciso/Cn ratio of 4.6, the highest value of gasoline-ranged hydrocarbons among the relevant reports.

Pt nanocatalysts loaded on reduced graphene oxide (Pt/RGO) were prepared by means of a convenient microwave-assisted reduction approach with ethylene glycol as reductant. The conversion of cellulose or cellobiose into sorbitol was used as an application reaction to investigate their catalytic performance. Various metal nanocatalysts loaded on RGO were compared and RGO-supported Pt exhibited the highest catalytic activity with 91.5 % of sorbitol yield from cellobiose. The catalytic performances of Pt nanocatalysts supported on different carbon materials or on silica support were also compared. The results showed that RGO was the best catalyst support, and the yield of sorbitol was as high as 91.5 % from cellobiose and 58.9 % from cellulose, respectively. The improvement of catalytic activity was attributed to the appropriate Pt particle size and hydrogen spillover effect of Pt/RGO catalyst. Interestingly, the size and dispersion of supported Pt particles could be easily regulated by convenient adjustment of the microwave heating temperature. The catalytic performance was found to initially increase and then decrease with increasing particle size. The optimum Pt particle size was 3.6 nm. These findings may offer useful guidelines for designing novel catalysts with beneficial catalytic performance for biomass conversion.

Reduced graphene oxide (RGO) is one of the most promising catalyst supports because it has faintly acidic sites together with a large amount of functional groups on its surface. In this report, we prove that, for the first time, Pt-loaded RGO (Pt/RGO) is an efficient, robust, and durable catalyst for oxidizing 5-hydroxymethylfurfural (HMF) directly to 2,5-furandicarboxylic acid (FDCA) under mild conditions. The selectivity of FDCA reaches up to 84% along with 100% HMF conversion in the presence of excess base. We deduce that the total reaction on the Pt/RGO catalyst includes several consecutive steps, in which 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) acts as an intermediate. The finding in this report is a significant advancement not only for RGO-based catalyst development, but also for scalable FDCA production, because the total reaction is performed smoothly without using the previously reported harsh reaction conditions.

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