Coverage-dependent acrylonitrile adsorption and electrochemical reduction kinetics on Pb electrode

Acrylonitrile Conversion on Metal Cathodes: How Surface Adsorption Determines the Reduction Pathways

“…Compared with the traditional butadiene hydrocyanation route, the EHD method avoids the usage of highly toxic and volatile hydrocyanic acid and can be achieved in a single reaction step; therefore, it is more advantageous in the future. , Unlike the other aforementioned electrochemical reduction processes, the product of dimerization rather than hydrogenation is desired during AN reduction. Since Pb and Cd electrodes are used in industrial processes, most of the studies regarding the generation of propionitrile (PN) and ADN are resulted from direct electron reduction without any catalytic effect. − Earlier studies reported that AN is coadsorbed with a quaternary ammonium salt on the cathode, and EHD takes place through a radical–substrate coupling step in the adsorbed state. , Montenegro and Pletcher pointed out that the transfer of the first electron is the rate-determining step in the conversion of AN to ADN, which was also validated by our recent kinetic study . However, these understandings are different from the recently proposed mechanism in CO reduction. ,− In addition, the effect of hydrogen adsorption on the AN reduction pathway is still inconclusive.…”

“…18,19 Montenegro and Pletcher 20 pointed out that the transfer of the first electron is the rate-determining step in the conversion of AN to ADN, which was also validated by our recent kinetic study. 12 However, these understandings are different from the recently proposed mechanism in CO reduction. 8,21−23 In addition, the effect of hydrogen adsorption on the AN reduction pathway is still inconclusive.…”

“…So far, the EHD of acrylonitrile (AN) to adiponitrile (ADN) is the most successful electrochemical organic synthesis process with a global capacity of million tons per year, , where ADN is generated from the dimerization of AN on the cathode, accompanied by the hydrogenation to propionitrile (PN) and the hydrogen evolution reaction (HER). Meanwhile, the oxygen evolution reaction (OER) occurs on the anode (Scheme ).…”

Paired Electrolysis of Acrylonitrile and 5-Hydroxymethylfurfural for Simultaneous Generation of Adiponitrile and 2,5-Furandicarboxylic Acid

“…While the AN initial concentration increased from 0.57 to 1.70 M, the ADN selectivity gradually increased from 15.9% to 90.1%, confirming that the initial AN concentration plays a key role in affecting the ADN yield. Since the formation of 1 mol ADN requires 2 mol AN, a relatively high AN adsorption amount on the electrode surface is helpful for its dimerization to form ADN [45]. The areal production rate and energy productivity of ADN at −75mA cm −2 (Figure 6c) reached peak values of 0.58 kgADN•h −1 •cm −2 and 0.25 Within the anode potential window of 1.41-1.61 V (vs. RHE), the catalytic activity of NiMoP/NF for HMFOR was investigated in 1.0 M KOH and 10 mM HMF electrolyte.…”

Electrosynthesis of Adiponitrile with a Rotating Cylindrical Electrode

“…The electrolyte flowing through channels at a high velocity, 1–3 m s –1 , providing fast mass transport, is a method applied in commercial processes . Mathematical models of the reaction in a flow reactor with a recycle loop have been developed by Scott et al , In addition to flow systems, ,, magnetic stirrers, , rotating disk electrodes, ultrasonic systems, and potential pulsing have been reported to control or enhance the mass transport of AN. A rotating rod electrode (RRE) is a simple and effective tool for the study of ADN electrosynthesis detailed in our previous report .…”