Crystallinity Improvement of Covalent Triazine Frameworks Boosting Room Temperature Hydrogenation of Carbon Dioxide into Formic Acid

Covalent triazine frameworks (CTFs), as a novel class of porous organic materials with a high nitrogen content, exhibit significant potential for CO2 capture and conversion. In this study, we demonstrate the substantial improvement in performance associated with CTF crystallinity in the room temperature hydrogenation of CO2 to formic acid under base-additive-free conditions. Specifically, the highly crystalline CTF-based catalyst Pd/CTF200-PA presents an eight times higher catalytic activity than its low-crystalline counterparts, achieving a remarkable turnover frequency (TOF) of 30.3 h–1 at 298 K in a pure water medium, which is slightly greater than those recently reported under similar reaction conditions. Experimental characterization reveals enhanced metal–support interactions between the highly crystalline CTF and Pd nanoparticles, which increase the electron density of Pd, making it a more efficient center for H2 dissociation. This work opens new avenues for the application of highly crystalline CTFs in CO2 utilization.