Dehydrogenation of 2,3-Butanediol to Acetoin Using Copper Catalysts

Abstract

2,3-Butanediol (2,3-BDO) was converted to 3-hydroxy-2-butanone (acetoin) using a heterogeneous catalyst having dehydrogenation activity. Copper-supported alumina (Cu-Al2O3) and zirconia (Cu-ZrO2) were investigated in the catalytic gas-phase reaction of 2,3-BDO in a fixed bed reactor. The results showed that these catalysts can convert 2,3-BDO to acetoin with selectivity reaching 96% at 170 °C at a conversion of 63% over Cu-Al2O3. The effects of copper loading, reaction temperature, and H2 on product selectivity were studied. Increasing copper loading led to higher acetoin selectivity on Cu-Al2O3. Increasing the temperature decreased acetoin selectivity on both catalysts due to increased production of 2,3-butanedione through dehydrogenation of acetoin. The presence of hydrogen is generally detrimental to acetoin production because it slows dehydrogenation of 2,3-BDO, although it also slows the rate at which acetoin is dehydrogenated to 2,3-butanedione. The number and strength of acid sites appear to be the likely explanation for why Cu-ZrO2 generally gives higher acetoin selectivity compared to Cu-Al2O3.

Vapor-Phase Oxidant-Free Dehydrogenation of 2,3- and 1,4-Butanediol over Cu/SiO2 Catalyst Prepared by Crown-Ether-Assisted Impregnation

“…In the previous papers [38,40], it is notable that high AC selectivity is realized at a high temperature of 260 • C or higher if the formation of DA can be prevented at such high temperatures. The AC productivity of the 12C4-10Cu/SiO 2 catalyst was also higher than that of Cu-Al 2 O 3 [39] at the same reaction temperature of 170 • C. Table 3 shows the comparison of the catalytic activities of several Cu catalysts in the vapor-phase dehydrogenation of 1,4-BDO to GBL. The utilization of 12C4 as an organic additive was proven to generate a Cu catalyst with the largest SA Cu .…”

“…Cu-based catalysts have been employed for the dehydrogenation of BDOs. Recently, supported Cu catalysts, such as Cu/SiO2 [37,38], Cu-Al2O3 [39], and Li-CuZnAl [40], have been used as efficient catalysts for the dehydrogenation of 2,3-BDO to AC (Scheme 1a). Nevertheless, several issues, such as a high reaction temperature, low productivity, and long contact time, still need to be addressed.…”

Use of Biosourced Molecules as Liquid Organic Hydrogen Carriers (LOHC) and for Circular Storage

“…Thus, shifting the equilibrium is possible by simple separation at temperatures between both boiling points. The dehydrogenation of 2,3-butanediol was also studied by Al-Auda et al, using a Cu-Al 2 O 3 catalyst [66] with the objective of a selective synthesis of acetoin (partial dehydrogenation).…”

Production of Butane from Methyl Ethyl Ketone over Pt/Al2O3

“…The catalyst (platinum supported on alumina) was synthesized using the incipient wetness impregnation method as the previous work [41]. [Pt(NH3)4(NO3)2] was used as a metal precursor after dissolving in a known amount of de-ionized water to fill the pores of amount of the Al2O3 as a support.…”