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A series of Pd−WO x /Al 2 O 3 catalysts with different contents of WO x were prepared by stepwise incipient wetness impregnations. The influence of WO x on the physicochemical properties of Pd−WO x /Al 2 O 3 catalysts, as well as their catalytic performance for the hydrogenolysis of glucose to 1,2-propanediol (1,2-PDO), was investigated. At low surface W density (0.3−2.1 W nm −2 ), distorted isolated WO x and oligomeric WO x are present on the Pd−WO x /Al 2 O 3 catalysts. Furthermore, isolated WO 4 are the dominating species on the Pd−WO x (5%)/Al 2 O 3 catalyst. When the W density increased to 3.1 W nm −2 , polymeric WO x species are dominant on the Pd−WO x (30%)/Al 2 O 3 catalyst. The Pd surface area decreased while the acid amount increased with increasing W density. Furthermore, increased Lewis acid sites are provided by isolated WO 4 and oligomeric WO x species whereas increased Brønsted acid sites exist on polymeric WO x species. Lewis acid sites promote glucose isomerization to fructose, which is an intermediate in glucose hydrogenolysis to 1,2-PDO. Metal sites catalyze CO hydrogenation and C−C hydrogenolysis, which avoid the coke formation on catalysts. 1,2-PDO selectivity is dependent on the synergy of Lewis acid and metal sites; however, Brønsted acid sites have no contribution to the 1,2-PDO production. Typically, the Pd−WO x (5%)/Al 2 O 3 catalyst possessing the optimal balance of Lewis acid and the metal site shows a 1,2-PDO selectivity of 60.8% at a glucose conversion of 92.2% and has a lifetime of over 200 h.

The one-step hydrogenolysis of biomass-derived glycerol to propanols (1-propanol + 2-propanol), which are known as biopropanols, was investigated over different supported Pt-H 4 SiW 12 O 40 (HSiW) bi-functional catalysts in aqueous media. Among the catalysts/supports tested, Pt-HSiW supported over ZrO 2 converted glycerol to biopropanols with high selectivity and high yield (94.1%), while exhibiting long-term stability (160 h). In addition, this catalyst can be resistant to the impurities present in crude glycerol. The reaction pathway to propanols from glycerol is proposed to proceed mainly through 1,2-propanediol. With the strategy toward one-step hydrogenolysis of glycerol to biopropanols sustainably, the biomass can be readily transformed to biodiesel and biopropanols via glycerol, which will bring about the benign development of the biodiesel industry. † Electronic supplementary information (ESI) available. See

Hydrogenolysis of glycerol to 1,3-propanediol in aqueous-phase was investigated over Pt-H 4 SiW 12 O 40 / SiO 2 bi-functional catalysts with different H 4 SiW 12 O 40 (HSiW) loading. Among them, Pt-15HSiW/SiO 2 showed superior performance due to the good dispersion of Pt and appropriate acidity. It is found that Brønsted acid sites facilitate to produce 1,3-PDO selectively confirmed by Py-IR. The effects of weight hourly space velocity, reaction temperature and hydrogen pressure were also examined. The optimized Pt-HSiW/SiO 2 catalyst showed a 31.4% yield of 1,3-propanediol with glycerol conversion of 81.2% at 200°C and 6 MPa.

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