3D-printing advanced ZIF-67@aluminum phosphate/Al₂O₃ ceramic catalyst by aluminum phosphate-assisted surface bonding

The 3D-printed ceramic catalyst has a broad range of application prospects. Notably, the ZIF-67-loaded 3D-printed ceramic catalyst demonstrates exceptional catalytic performance and a high degree of structural design flexibility. However, the ceramics prepared by the direct loading of ZIF-67 onto ceramic substrates during 3D printing show insufficient catalytic stability. In this study, aluminum phosphate (AP) was used as a binder to enhance the adhesion between ZIF-67 and the Al₂ O₃ ceramic support surface, thereby reducing ZIF-67 shedding and preventing the degradation of the catalytic performance of the 3D-printed ceramic catalyst. Consequently, after six cycles, the conversion rate of 4-nitrophenol with ZIF-67/Al₂ O₃ decreased by 31%, whereas that with ZIF-67@AP/Al₂ O₃ decreased by only 5.4%. The reasons for the high catalytic stability of ZIF-67@AP/Al₂ O₃ were comprehensively and meticulously investigated. The proposed synthesis strategy, which utilizes AP to facilitate the bonding of ZIF-67 to the Al₂ O₃ ceramic scaffold, offers a novel approach for enhancing the catalytic stability of 3D-printed ceramic catalysts loaded with active species through self-growth methods. This approach is expected to guide future research on efficient catalytic systems for various applications.