Carbon nanofibers supported Ru catalyst for sorbitol hydrogenolysis to glycols: Effect of calcination

Abstract

Carbon nanofiber (CNFs) supported Ru catalysts for sorbitol hydrogenolysis to ethylene glycol and propylene glycol were prepared by incipient wetness impregnation, calcination and reduction. The effect of calcination on catalyst properties was investigated using thermal gravimetry analysis, temperature-programmed reduction, X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and N 2 physisorption. The results indicated that calcination introduced a great amount of surface oxygen-containing groups (SOCGs) onto CNF surface and induced the phase transformation of Ru species, but slightly changed the texture of Ru/CNFs. The catalytic performance in sorbitol hydrogenolysis showed that Ru/CNFs catalyst calcined at 240 o C presented the highest glycol selectivities and reasonable glycol yields. It was believed that the inhibition and confinement effect of SOCGs around Ru particles as well as the high dispersion of Ru particles was the key factor for the catalytic activity.

Selective terminal C–C scission of C5-carbohydrates

“…A difference in the order of appearance of the epimerisation products was observed for both pentoses. Xylitol was first mainly converted into arabitol (Table 2, entry 12) and subsequently into adonitol ( Table 2, entries [14][15][16][17]. This can on one hand be simply rationalised based on statistics; epimerisation at both C2 and C4 of xylitol yields arabitol, while only epimerisation at C3 can yield adonitol.…”

Synthesis of Nanoparticles for Biomass Conversion Processes

“…Others (133)(134)(135)(136)(137) have suggested that the primary use of a base promoter is to prevent leaching of metal particles from the catalyst. Zhao et al confirmed that the base promoter could improve sorbitol hydrogenolysis by neutralizing the organic acids derived from side-reactions (131,132). It is apparent from these studies that NPs are emerging as central catalysts for important reactions relevant to biorenewables transformation.…”

“…Typically, Ru NP catalysts are synthesized and supported on a surface to create a heterogeneous catalyst. The support can be in the form of polymers, silica, carbon, carbon nanofibers (84) or carbon nanotubes (85)(86)(87). Metallic NPs can be synthesized in several ways by utilizing different metal salts, reducing agents and stabilizers.…”

“…For example, Zhao et al developed a Ru catalyst supported on carbon nanofibers (CNF) for the hydrogenolysis of sorbitol to ethylene glycol and propylene glycol (131,132). A proposed adopted mechanism is shown in Figure 2 (132).…”

Sorbitol Hydrogenolysis to Glycols over Baisic Additive Promoted Ni-based Catalysts

“…Currently, conventional hydrogenation catalysts such as Ni, Cu, Ru, and Pt [9−17] based catalysts were mainly used for the sorbitol hydrogenolysis. For example, Zhao et al prepared Ru/CNFs by incipient wetness impregnation for sorbitol hydrogenolysis and the higher activity and selectivity for glycols were obtained compared with Ru supported on commercial activated carbon [14,16]. Banu et al reported that 1,2-propanediol was the major product in sorbitol hydrogenolysis using Ni/NaY as the catalyst, however, when Ni was replaced by Pt, glycerol was presented as the main product in the same process [9,17].…”