Integrated Capture and Electroreduction of Low‐Concentration CO₂ to CO Using Geopolymer|Graphene‐Cobalt Phthalocyanine Composite

Green electricity‐driven electrocatalytic CO 2 reduction (e‐CO 2 RR) has emerged as a promising approach to upcycle CO 2 into valuable chemicals and fuels, paving the way for a carbon‐neutral economy. The success of such a device relies on the development of cost‐effective catalysts that can efficiently and selectively catalyze e ‐CO 2 RR. In the present contribution, the high activity and selectivity of graphene‐supported CoPc (graphene‐CoPc) are demonstrated toward CO generation from e ‐CO 2 RR by encapsulating graphene|CoPc into Perlite–Metakaolin‐based geopolymer (geopolymer|graphene‐CoPc). The high electric conductivity (3.52 ± 0.4 S m −1 ) and CO 2 adsorption capability (0.16 mmol CO 2 g −1 ) of the geopolymer matrix, obtained through the systematic investigation and optimization of synthetic conditions, facilitate the charge transfer and provide high local CO 2 concentration. Consequently, this significantly enhancing both turnover frequency (2.3 ± 0.3 s −1 ) and Faradaic efficiency (93.7 ± 3.1%) of geopolymer|graphene‐CoPc for CO production from the low‐concentration CO 2 (≈40%) in simulated biogas atmosphere at a low η of 0.69 V as compared to the pristine graphene‐CoPc (turnover frequency: 1.37 ± 0.1 s −1 and Faradic efficiency: 46.3 ± 2.0%).