1 Photoelectrochemical reactors for CO2 utilization Sergio Castro * , Jonathan Albo and Angel Irabien Department of Chemical & Biomolecular Engineering, University of Cantabria, Avda. Los Castros s/n, 39005 Santander, Spain *Corresponding author, email: sergio.castro@unican.es ABSTRACT The photoelectrochemical reduction of CO2 to renewable fuels and valuable chemicals using solar energy is a research topic that has attracted great attention recently due to its potential to provide value added products under the sun, solving the issues related to global warming at the same time. This review covers the main research efforts made on the photoelectrochemical reduction of CO2. Particularly, the study focuses in the configuration of the applied reactor, which is a topic scarcely explored in the literature. This includes the main materials used as photoelectrodes and their configuration in the photoelectrochemical reactor, which are discussed for technical uses. The review provides an overview of the state-of-the-art and aims to help in the development of enhanced photoelectroreactors for an efficient CO2 utilization. KEYWORDS: Photoelectrocatalysis; CO2 reduction; reactor configurations; photoelectrodes; climate change INTRODUCTION The reduction of fossil fuels and the growing emission of carbon dioxide (CO2) have accelerated research activities to produce fuels and chemicals from wasted CO2 as a Page 1 of 70 ACS Paragon Plus Environment ACS Sustainable Chemistry & Engineering 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60