One-Pot Production of Lactic Acid from Acetol over Dealuminated Sn-Beta Supported Gold Catalyst

Abstract

Staged biomass pyrolysis or condensation of the pyrolysis vapor generates less complex and concentrated liquid product streams, which provide a very promising route to produce value-added chemicals. Acetol is one of the major light oxygenates in fractionated bio-oil. Here we report an efficient one-pot conversion of acetol to lactic acid, a key platform chemical and an important monomer of biodegradable polymer, in aqueous phase over a bifunctional dealuminated Sn-Beta supported gold catalyst. Under relatively mild conditions (393 K, 1.9 MPa N2 + 0.1 MPa O2), 93.4% acetol conversion and 73.2% selectivity toward lactic acid were achieved. On the basis of measured rate constants, the reaction pathway likely proceeds via kinetically relevant oxidation of acetol to form pyruvaldehyde, followed by hydration and 1,2-hydride shift (internal Meerwein–Ponndorf–Verley reduction and Oppenauer oxidation) on Sn-Lewis sites to produce lactic acid.

Oxidative esterification of acetol with methanol to methyl pyruvate over hydroxyapatite supported gold catalyst: Essential roles of acid-base properties

“…occurred on both carbonyl groups, it can also undergo Cannizzaro reaction [8,9] under relatively strong alkaline support or 1,2-hydride shift upon Lewis acid [7], leading to the formation of MLA, as also evidenced from entry 7 of Table 4 in our work. All these demonstrate that the base strength in the catalyst support is the very delicate and elegant part to successfully manipulate the selectivity over the varied products.…”

“…It is highly desired to convert acetol to stable and value-added chemicals. Our recent work showed that with dealuminated Sn-beta supported gold catalyst under base-free conditions, acetol can be selectively con-verted to lactic acid [7] with a higher yield and improved catalyst stability compared to the earlier literature reports with inorganic base addition or base supported catalysts [8,9]. Herein we report that another important chemical, namely methyl pyruvate, can be synthesized from acetol via oxidative esterification over Au-based catalysts, further diversifying the applications of acetol derived from renewable biomass.…”

Conversion of Sucrose into Lactic Acid over Functionalized Sn-Beta Zeolite Catalyst by 3-Aminopropyltrimethoxysilane

“…Wan et al reported an efficient one-pot conversion of acetol to LA over a bifunctional dealuminated Sn-Beta-supported gold catalyst. 25 The synthesis process of Au/deAl-Sn-Beta catalyst mainly involves two steps, namely the SSIE procedure to form deAl-Sn-Beta zeolite and thereafter the sol immobilization method to load Au on the support synthesized before. Xia et al also reported a bimetal-modified Beta zeolite Pb–Sn-Beta catalyst synthesized by SSIE for converting carbohydrates into LA.…”

Selective Conversion of Cellulose to Hydroxyacetone and 1‐Hydroxy‐2‐Butanone with Sn–Ni Bimetallic Catalysts

“…[16,17] Most researchers have focused on enhancing the hydrogenation activity and selectively cleaving CÀCb onds to catalyze the hydrolysis of cellulose. [22][23][24][25][26] HA is currently produced mainly by oxidation of 1,2propanediol, which,i nt urn, is produced mainly from petropropylene via epoxy compounds. [18][19][20][21] For some compounds, their unsaturated C=Obond makes them exhibit special features.…”

“…In particular, HA is an important intermediate used to produce polyols, acrolein, methylglyoxal, acetone, and lactic acid or directly used as food addictive, reducinga gent, and so on. [22][23][24][25][26] HA is currently produced mainly by oxidation of 1,2propanediol, which,i nt urn, is produced mainly from petropropylene via epoxy compounds. [25,27,28] It also can be obtained by direct conversion cellulose over Ni-based catalysts such as Ni-SnO x /Al 2 O 3 or single-atom Ni catalysts.…”