Ultrafine Pd nanoparticles anchored on hierarchically porous titanium-based MOFs for superior photothermal CO2 reduction

The exploration of robust titanium-based metal-organic framework (MOF) photocatalysts for efficient CO2 reduction is of critical significance but remains challenging. Herein, a hierarchically porous titanium-MOF (hMUV-10) anchored with ultrafine Pd nanoparticles was rationally designed via a convenient one-step in-situ water-etching strategy. The hierarchical MUV-10 structure provided abundant sites for the anchoring of Pd nanoparticles on the outside and inside of MOFs. The optimized Pd/hMUV-10 demonstrated an ultrahigh CO production rate of 65.9 mmol g(-1) h(-1) under light irradiation at 350 degrees C, approximately two orders of magnitude higher than the state-of-the-art MOF-based catalysts and surpassed most reported inorganic semiconductor-based catalysts. The CO production rate under a relatively mild temperature of 200 degrees C also reached as high as 3.36 mmol g(-1) h(-1), and negligible activity decay was observed during continuous cycling measurement under 350 degrees C. Theoretical calculations suggested that Pd enhanced CO2 adsorption ability and reduced the energy barrier for CO2 reduction, thereby leading to a highly improved CO yield from photothermal CO2 reduction.

Automated summary

A hierarchically porous titanium-MOF (hMUV-10) anchored with ultrafine Pd nanoparticles was designed via a one-step in-situ water-etching strategy. The optimized Pd/hMUV-10 demonstrated an ultrahigh CO production rate and negligible activity decay during continuous cycling measurement.