PdH_x Entrapped in a Covalent Triazine Framework Modulates Selectivity in Glycerol Oxidation

Pd nanoparticles within a nitrogen-containing covalent triazine framework (CTF) material are investigated to understand if the highly tunable CTF chemistry mediates the catalytic properties of the Pd nanoparticles. Surprisingly, our results demonstrate that the CTF stabilizes the formation of 2.6 nm PdH_x particles within the pores. These confined PdH_x particles are very active for the liquid-phase oxidation of glycerol and promote C-C cleavage, probably connected with the enhanced in situ formation of H₂O₂. During recycling tests, the confined particles are transformed progressively to very stable Pd⁰ particles. This stability has been attributed mainly to a confinement effect as nanoparticles trapped outside the pores lose activity rapidly. These results indicate that there is a potential to tune CTF chemistry to modify the chemistry of the catalytic metals significantly.