Synthesis of SAPO-34 Nanoplates with High Si/Al Ratio and Improved Acid Site Density

Abstract

Two-dimensional SAPO-34 molecular sieves were synthesized by microwave hydrothermal process. The concentrations of structure directing agent (SDA), phosphoric acid, and silicon in the gel solution were varied and their effect on phase, shape, and composition of synthesized particles was studied. The synthesized particles were characterized by various techniques using SEM, XRD, BET, EDX, and NH3-TPD. Various morphologies of particles including isotropic, hyper rectangle, and nanoplates were obtained. It was found that the Si/Al ratio of the SAPO-34 particles was in a direct relationship with the density of acid sites. Moreover, the gel composition and preparation affected the chemistry of the synthesized particles. The slow addition of phosphoric acid improved the homogeneity of synthesis gel and resulted in SAPO-34 nanoplates with high density of acid sites, 3.482 mmol/g. The SAPO-34 nanoplates are expected to serve as a high performance catalyst due to the low mass transfer resistance and the high density of active sites.

Promoter Impact on 5Ni/SAPO-5 Catalyst for H2 Production via Methane Partial Oxidation

“…There were significantly more acid sites observed on the 5Ni+1Sr/SAPO-5 catalyst (1.65 mmol/g) than on the 5Ni/SAPO-5 catalyst (1.03 mmol/g). It shows that a broad range of acid strengths were exhibited by all of the catalysts that were generated [44]. It was observed that the catalysts 5Ni+1Ce/SAPO-5 and 5Ni+1Cu/SAPO-5 only showed a single peak at about 300 • C, but the supported catalysts, 5Ni +1Sr/SAPO-5, had two peaks at 300 • C and 480 • C [45,46].…”

Nanomaterials for Membranes, Membrane Reactors, and Catalyst Systems

“…The obtainment and application of nanomaterials in the form of the film have found excellent uses of great technological utility [ 8 , 9 , 10 ], even reaching the needs of aerospace and advanced manufacturing technology [ 11 ].…”