Electrocatalysis for organic chemical production will likely play a large role in the future of the chemical industry. Electrocatalytic methods have proven to be able to synthesise an array of valuable chemicals, from, for example, CO₂ making alcohols and hydrocarbons. From these products (e.g. methanol and CO) further reactions can be performed, such as the carbonylation of methanol to form dimethyl carbonate (DMC, CH₃OCOOCH₃)¹. DMC is a valuable commodity chemical used to make polycarbonates, is a solvent in lithium-ion batteries and is used as a carbonylation reagent in pharmaceutical industry. Currently, DMC is produced using thermal catalysis at high temperature and pressure. A viable electrocatalysis synthesis route requires high reaction efficiency and selectivity. However, the task of improving reaction selectivity is challenging, and determination of reaction intermediates and products is vital to understanding how to optimise for a desired product. With in situ techniques, such as online-gas chromatography and mass spectroscopy and FTIR spectroelectrochemistry we have investigated the electrochemical synthesis of DMC on different transition metal electrodes. DMC can be formed on Au and Pd though heterogeneous electrocatalysis² and on Cu we have shown that the reaction takes places in solution, though a homogenous electrocatalytic step³. In the heterogeneous route on both metals, a major co-product is produced from the bicarbonylation of methanol as dimethyl oxalate (DMO). The main reaction intermediates are proposed to be CH₃O* and CH₃OCO*, the former resulting in DMC and the latter producing the co-product, DMO. Therefore, efforts to selectivity bind the CH₃O* intermediate might result in a high DMC product selectivity and efficiency. The knowledge of the reaction selectivity and methodologies of analysis techniques is likely transferable to other syntheses involving simple organic molecules. Different methods of describing selectivity will also be discussed. Development of an efficient process could result in a viable sustainable synthesis route for DMC, making a step towards a renewable energy and materials based chemical industry.

1. Šarić, M. et al. Green Chem. 21, 6200–6209 (2019)

2. Davies, B. J. V., et al. J. Phys. Chem. C 123, 12762–12772 (2019),

3. Davies, B. J. V. et al. ACS Catal. 9, 859–866 (2019).