Highly Tunable Syngas Product Ratios Enabled by Novel Nanoscale Hybrid Electrolytes Designed for Combined CO<sub>2</sub> Capture and Electrochemical Conversion
Tony G. Feric, Sara T. Hamilton, Byung Hee Ko, Gahyun Annie Lee, Sumit Verma, Feng Jiao, Ah‐Hyung Alissa Park
Abstract
Abstract Coupling renewable energy with the electrochemical conversion of CO 2 to chemicals and fuels has been proposed as a strategy to achieve a new circular carbon economy and help mitigate the effects of anthropogenic CO 2 emissions. Liquid‐like Nanoparticle Organic Hybrid Materials (NOHMs) are composed of polymers tethered to nanoparticles and are previously explored as CO 2 capture materials and electrolyte additives. In this study, two types of aqueous NOHM‐based electrolytes are prepared to explore the effect of CO 2 binding energy (i.e., chemisorption versus physisorption) on CO 2 electroreduction over a silver nanoparticle catalyst for syngas production. Poly(ethylenimine) (PEI) and Jeffamine M2070 (HPE) are ionically tethered to SiO 2 nanoparticles to form the amine‐containing NOHM‐I‐PEI and ether‐containing NOHM‐I‐HPE, respectively. At less negative cathode potentials, PEI and NOHM‐I‐PEI‐based electrolytes produce CO at higher rates than 0.1 molal. KHCO 3 due to favorable catalyst‐electrolyte interactions. Whereas at more negative potentials, H 2 production is favored because of the carbamate electrochemical inactivity. Conversely, HPE and NOHM‐I‐HPE‐based electrolytes display poor CO 2 reduction performance at less negative potentials. At more negative potentials, their performance approached that of 0.1 molal. KHCO 3 , highlighting how the polymer functional groups of NOHMs can be strategically selected to produce value‐added products from CO 2 with highly tunable compositions.