Pure CoAPO-36 crystal grains were synthesized by hydrothermal reaction. Porous α-Al2O3, stainless steel and K2Ti6O13 supported CoAPO-36 films were fabricated using in situ crystallization for the first time. SEM images and XRD measurements demonstrate that a continuous CoAPO-36 film was obtained on the K2Ti6O13 substrate. Diffuse reflectance UV-Vis spectra indicate that Co2+ has been incorporated into the ATS framework. Both CoAPO-36 crystal grains and the K2Ti6O13 supported CoAPO-36 film exhibit satisfactory catalytic activities for the oxidation of cyclohexane.
WANG XiaoHuiLI JianWANG YanJiZHANG BaoQuanLIU XiuFeng
The acid-base titration,atomic force microscopy(AFM),contact angle technique,energy dispersive X-ray(EDX)and electron probe microanalysis(EPMA)were performed to check the existence of the gel-layer on the chitosan surface after it was dipped in aqueous TPAOH solution as well as in TS-1 synthesis solution.The evolution of TS-1 monolayer and multi-layered film on the chitosan surface was studied using SEM imaging at different stages during hydrothermal reactions.Experimental evidence for the formation mechanism of supported zeolite films and membranes revealed that a gel-layer enriched with TPA cations and TS-1 precursors was first formed on the chitosan surface,followed by the nucleation within the gel-layer especially on the chitosan surface.The nuclei formed on the chitosan surface were further transformed into crystalline particles and TS-1 crystal grains.The nuclei beyond the chitosan surface subsequently grew up,leading to the formation of multi-layered TS-1 film with preferential b-orientation.The result is significant for engineering the microstructure of supported zeolite films and membranes in hydrothermal reactions.
LIU XiuFengWANG XiaoDongNA PingJIANG HaiYangLANG LinZHAO HongSheZHANG BaoQuan
