Search

[Display omitted] • Rod-shaped CeO 2 supported AuPd alloy structure was facilely synthesized. • Au 1 Pd 1 /CeO 2 showed remarkable increase in hydrogenolysis activity of aryl C O bond. • The strength of aryl C–O ether bond of lignin is decreased as 4-O-5 > β-O-4 ≥ α-O-4. • Au 1 Pd 1 /CeO 2 obtained 44.1% yield of monophenols in hydrogenolysis of real lignin. The mild depolymerization of lignin into aromatic monomer is a grand challenge owing to the various aryl ether C–O bonds, particularly for the most abundant β-O-4, α-O-4 and 4-O-5 linkages. Rod-shaped CeO 2 supported AuPd bimetallic catalysts fabricated by sol-immobilization method presented robust alloy structure, as evidenced by TEM, XPS, UV–vis, and CO-DRIFTS. For the hydrogenolysis of C O bond model compound with formic acid, Au 1 Pd 1 /CeO 2 showed about 23.5 and 6 folds increase in activity compared with its monometallic counterparts Au/CeO 2 and Pd/CeO 2 , respectively. The outstanding performance was mainly ascribed to the increased adsorption ability of electron-deficient Pd for aromatic C–O bond. Additionally, formic acid-mediated Au 1 Pd 1 /CeO 2 has efficiently performed hydrogenolysis of real lignin into a variety of valuable monophenols, achieving 44.1% yield at low temperature. [ABSTRACT FROM AUTHOR]

Despite 1,3-propanediol possessing high economic value, its production from glycerol hydrogenolysis is a challenging task. Herein, a series of WO x promoted Pt/Al 2 O 3 catalysts with various WO x contents were prepared and investigated for selective production 1,3-propanediol from glycerol hydrogenolysis. To explore the structure feature, these catalysts were fully characterized by BET, CO chemisorption, HRTEM, XRD ( in situ XRD), Raman, NH 3 –TPD, Py–IR, H 2 –TPR, and XPS. Among them, Pt–10WO x /Al 2 O 3 achieved the highest 1,3-propanediol yield up to 42.4%, which was ascribed to the large concentration of Brønsted acid sites, strong electronic interaction between Pt with WO x and hydrogen spillover. The strong correlation between 1,3-propanediol yield and Brønsted acid site indicated its essential role for the formation of 1,3-propanediol. Meanwhile the linear correlation between 1,2-propanediol yield and Lewis acid site gave direct evidence that Lewis acid site preferentially generated 1,2-propanediol. [ABSTRACT FROM AUTHOR]

Highlights: [•] Addition of SiO2 to PtW/Zr greatly enhanced activity and 1,3-propanediol selectivity. [•] 54.3% conversion and 52.0% 1,3-propanediol selectivity were achieved over 5PtW/ZrSi. [•] A model scheme of WO x transformation due to SiO2 doping has been built. [•] Pt and polytungstate have been identified as the dominant active phases. [•] Glycerol hydrogenolysis conforms to the dehydration–hydrogenation mechanism. [Copyright &y& Elsevier]

Highlights: [•] Alkaline metals Li, K, Rb and Cs were efficient for tune acidity of H4SiW12O40. [•] Li modified Pt–H4SiW12O40/ZrO2 exhibited superior 1,3-propanediol selectivity. [•] 1,3-Propanediol yield was proportional to the concentration of Brønsted acid sites. [•] A mechanistic scheme for glycerol hydrogenolysis to 1,3-propanediol was proposed. [•] A 120h long-term performance for Pt–H4SiW12O40/ZrO2 was achieved. [ABSTRACT FROM AUTHOR]