Effect of Metals on the Hydrogenolysis of Glycerol to Higher Value Sustainable and Green Chemicals Using a Supported HSiW Catalyst

Abstract

Pt, Pd, Ni, and Cu supported on HSiW/Al2O3 catalysts were studied for the hydrogenolysis of glycerol. It was found that Pt is the best promoter for the production of 1,3-propanediol (1,3-PD) and 1-propanol (1-PO). Ni, a much cheaper metal, has fairly comparable reactivity to Pt, while Cu does not show any activity for the production of 1,3-PD. The catalysts were characterized by XRD and NH3-TPD. The strength of the acid sites affects the distribution of products. A reaction mechanism for a NiHSiW/Al2O3 catalyst involving rate-determining parallel dehydration of primary alcohol to produce acetal and of secondary alcohol to produce 3-hydroxypropylaldehdye (3-HPA) was proposed. Hydrogenolysis of 1,3-PD is 15 times slower than that of 1,2-PD. Most of the 1-PO is derived from 1,2-PD. An optimal balance of acid sites of appropriate acid strength and hydrogenation sites will lead to a highly selective catalyst for the production of higher value sustainable chemicals from glycerol.

Effect of support acidity during selective hydrogenolysis of glycerol over supported palladium–ruthenium catalysts

“…[37] This type of consecutive hydrogenolysis is one of the reasons for the difficulty in achieving high conversion of glycerol and high selectivity of 1,2-PDO at longer reaction times. [7,34,[38][39][40] In our investigation, most of the catalysts showed relatively higher selectivity to propane after 16 h reaction ( Table 2 and Figure -C) which supports this. At much longer reaction times, i.e.…”

“…The production of 1-PO via the hydrogenolysis of 1,2-PDO under relatively mild conditions has been reported [38]. This type of consecutive hydrogenolysis is one of the reasons for the difficulty in achieving high conversion of glycerol and high selectivity of 1,2-PDO at longer reaction times [7,35,[39][40][41]. In our investigation, Ti 0.9 W 0.1 O 2 supported catalyst showed relatively higher selectivity to propane after 16 h reaction (table 2; figure 2c) which supports this.…”

High Yield to 1-Propanol from Crude Glycerol Using Two Reaction Steps with Ni Catalysts

“…At 260 • C and after 5 h of reaction (Test 10), a yield to 1-POH of 71% can be obtained, comparable with other catalytic systems reported in the literature such as Pt/Zr 0.7 Al 0.3 O y [13], and this is a yield superior to that obtained with Ni/SiO 2 and Ni/Al 2 O 3 [20], Pd/MoO 3 -Al 2 O 3 [28], Pt/HSiW-Al 2 O 3 [21], and Pt/PTA-ZrO 2 [11].…”

“…As previously reported by several authors, 1,2-PG is obtained by a first dehydration stage of C-O bond cleavage reaction from glycerol molecule and a subsequent hydrogenation stage, while 1-POH can be obtained through the subsequent hydrogenolysis of 1,2-PG [16][17][18]. However, in the literature, there are more scientific contributions focused on glycerol hydrogenolysis to produce 1,2-PG than to produce 1-POH [19,20], though the latter is also a high value-added product [21].…”

Effect of Tungsten Species on Selective Hydrogenolysis of Glycerol to 1,3‐Propanediol

“…Moreover, the yield of 1,3‐PDO is closely related to the amount of Brønsted acid sites in the hydrogenolysis of glycerol [74] . Various metals (Pt, Pd, Rh, Ru, Ir, Au, Ni, and Cu) were studied as the active sites in tungsten‐containing catalysts [51,62,76,88] . Among them, the Pt−W‐based catalysts were recognized as the best choice for the selective production of 1,3‐PDO, which benefited from the excellent hydrogen activation ability of Pt and synergistic effect between Pt and tungsten species.…”