Eco-Friendly Synthesis of Cobalt Phthalocyanine for High-Efficiency CO 2 Electroreduction

We report a sustainable and cost-effective synthesis of cobalt phthalocyanine (CoPc) using low-impact solvents and a streamlined purification procedure, achieving an 85% yield with limited waste generation, as indicated by an environmental factor (E-factor) of 18.6. This route provides an eco-friendly approach to producing a molecular electrocatalyst for ${\mathrm{CO}}_2$ reduction. The catalytic activity of the synthesized CoPc is validated by its integration into a gas diffusion electrode with carbon nanotube supports, exhibiting methanol production with a Faradaic efficiency up to 12%, matching the values reached with the conventionally synthesized counterparts. Notably, under high loading (micrometric crystallites of CoPc), ${\mathrm{CO}}_2$ -to-CO conversion reached 65%, in fair alignment with literature benchmarks. Our work shows that green synthesis can yield high-performance catalysts for ${\mathrm{CO}}_2$ electrochemical reduction ( ${\mathrm{CO}}_2\mathrm{RR}$ ), enabling sustainable methanol production.