Combining Chemical and Microbial Electrocatalysis for CO2 Utilisation

Summary

Carbon dioxide (CO₂) is a major greenhouse gas, and it is important to develop methods to convert it to useful products (e.g., chemicals, biofuels). Electrocatalytic conversion of CO₂ is promising, as it does not require high temperatures and pressures (which consume a lot of energy), or complex solvents (which consume a lot of resources). Two types of electrocatalysts have received a lot of attention: solid metal catalysts, and microorganisms (i.e., biocatalysts). Recently, the combination of metals and microorganisms has been proposed, because this results in improved overall catalytic performance. Here, all the positive and negative effects from this combination are investigated in detail. The effects are differentiated between catalytic (e.g., when the product of one catalyst is converted by the other) and non-catalytic effects (e.g., when the presence of one catalyst affects the structure or activity of the other). With this deeper understanding, recommendations are given for improved electrocatalytic CO₂ conversion.