Upgrading of Ethanol to 1,1‐Diethoxyethane by Proton‐Exchange Membrane Electrolysis

Abstract

The direct acetalization of ethanol is a significant challenge for upgrading bioethanol to value‐added chemicals. In this study, 1,1‐diethoxyethane (DEE) is selectively synthesized by the electrolysis of ethanol using a proton‐exchange membrane (PEM) reactor. In the PEM reactor, a Pt/C catalyst promoted the electro‐oxidation of ethanol to acetaldehyde. The Nafion membrane used as the PEM served as a solid acid catalyst for the acetalization of ethanol and electrochemically formed acetaldehyde. DEE was obtained at high faradaic efficiency (78 %) through sequential electrochemical and nonelectrochemical reactions. The DEE formation rate through PEM electrolysis was higher than that of reported systems. At the cathode, protons extracted from ethanol were reduced to H2. The electrochemical approach can be utilized as a sustainable process for upgrading bioethanol to chemicals because it can use renewable electricity and does not require chemical reagents (e. g., oxidants and electrolytes).

Proton exchange membrane electrolysis of methanol for simultaneously synthesizing formaldehyde and hydrogen

“…55 Moreover, Nafion catalyzes the acetalization of ethanol and acetaldehyde to form 1,1-diethoxyethane. 47 To confirm whether Nafion could catalyze the acetalization of FA and MeOH to DMM, non-electrochemical acetalization of FA and MeOH was evaluated. The formation rates of DMM in MeOH/FA mixture solutions with and without the Nafion membrane are shown in Table 1.…”

Recent Advances in Upgrading of Low‐Cost Oxidants to Value‐Added Products by Electrocatalytic Reduction Reaction

“…[11][12][13][14][15][16] These shed light on decreasing overall cost without losing catalytic activity (Figure 2d). The other is replacing anodic oxygen evolution reaction (OER) with an alternative oxidation reaction to promote cathodic HER, such as urea, [17] hydrazine, [18] alcohols, [19,20] amine, [21,22] glucose, [23] and biomass-derived compounds oxidation. [24][25][26][27] Not only the overall cost of high energy consumption can be reduced, but valuable fuels (H 2 ) and chemicals (such as various hydrocarbon, aldehyde, ketone, carboxylic acid/carboxylate, even corresponding ester etc.)…”

“…For instance, H 2 can be evolved at the cathode without the potential explosion of the H 2 /O 2 mixture. At the same time, carboxylate, ketone, and even corresponding ester can be obtained from different alcohol oxidation; [19,20,39] furoic acid, maleic acid, 2,5-furandicarboxylic acid, and gluconate/xylonate can be achieved from biomass oxidation; [23][24][25]27,40,41] furthermore, dihydroisoquinolines, cyclooctene oxide, as well as polyethylene terephthalate plastic can be gained from corresponding substance oxidation. [42][43][44] Besides, some reviews have been published to guide researchers in focusing on this domain.…”

Heterostructured Ru/Ni(OH)2Nanomaterials as Multifunctional Electrocatalysts for Selective Reforming of Ethanol

“…Additionally, O 2 is a low-valued chemical. Replacing the normal oxygen evolution with the electrochemical reforming of proton-containing hydrogen chemicals has thus attracted increasing attention. ,− For example, the electrochemical reforming of ethanol can harvest green hydrogen energy and high value-added anode products. − However, the activity and selectivity of ethanol reforming are highly dependent on the catalysts; also, the catalysts should exhibit desirable performance for both ethanol reforming and hydrogen evolution. , Commercial Pt/C is currently the most superior bifunctional catalytic catalyst in the electrochemical ethanol reforming and hydrogen production, but the extremely low reserves and high costs limit their large-scale application. , As a consequence, the rational design of non-Pt-based multifunctional electrocatalysts is of high significance to open up new hydrogen production systems beyond water splitting.…”

“…Constructing heterostructures has proven to be a promising synthetic strategy for gaining unique multifunctional catalytic properties − as it can optimize the electron binding energy of the catalysts, regulating the absorption and desorption ability of the intermediates on the catalysts, and modifying the reaction pathway. ,,, Therefore, it is highly satisfying to synthesize a Ru-based heterostructured catalyst through a heterogeneity strategy with excellent abilities for both cathodic hydrogen evolution and anodic ethanol oxidation. Another major challenge is that ethanol oxidation involves multiple electron transfers as well as multiple functional group transformations, resulting in the diversity of products. ,,,,,− By regulating the Ru-based heterostructured catalysts, changing the electrochemical oxidation process of ethanol molecules, and harvesting a single high-value-added product through selective reformation, it will lead the development of selective electric reforming of biomass.…”