Synthesis and Characterization of ZSM-5 Zeolite Using Kaolin as Si and Al Source

Abstract

The objective of this work is to obtain synthesis of ZSM-5 zeolite using kaolin as Si and Al alternative source. Kaolin powder was dispersed under constant stirring into the sílica sol where the mass ratio of kaolin to silica was 1:2. After stirring for 2 hours, the dispersion was dried at 160 °C and calcined at 700 °C/2 hours. The synthesis of ZSM-5 zeolite was by hydrothermal treatment at 170 °C/48 hours under autogenous pressure. The materials were characterized by XRD, SEM, EDX, BET. According to the XRD, was possible to observe the formation of ZSM-5 zeolite with intense and well defined peaks set located between 2θ = 7-9° and 23-25°, typical of a crystalline material. The SEM showed the formation of particles clusters with orthorhombic shape characteristic of MFI structure. The results show that the hydrothermal treatment was efficient to produce ZSM-5 using calcined kaolin as alternative source.

Zeolite ZSM‐5 synthesized from natural silica sources and its applications: a critical review

“…reported, for the first time, a direct synthesis of high‐silica ZSM‐5 from Ahoko Nigerian Kaolin (ANK) without the need for an external silica source 158 . After a gel aging period of 36 h at ambient temperature, the hydrothermal synthesis of ZSM‐5 was carried out in a Teflon‐lined autoclave at 140 °C for 48 h. Since 2013, the number of publications related to the synthesis of ZSM‐5 from kaolin and its applications in catalytic processes has dramatically expanded 159‐166 . Several aspects have been discussed, including the absence of an organic template, the addition of another silica/alumina source, or the absence of calcination (as a prior pretreatment of kaolin).…”

“…158 After a gel aging period of 36 h at ambient temperature, the hydrothermal synthesis of ZSM-5 was carried out in a Teflon-lined autoclave at 140 °C for 48 h. Since 2013, the number of publications related to the synthesis of ZSM-5 from kaolin and its applications in catalytic processes has dramatically expanded. [159][160][161][162][163][164][165][166] Several aspects have been discussed, including the absence of an organic template, the addition of another silica/alumina source, or the absence of calcination (as a prior pretreatment of kaolin). For instance, Wang et al 159 and Pan et al 164 focused on the organic-template free synthesis of ZSM-5, while Shen et al 160 employed kaolin as the sole Si and Al source; also, Qoniah et al 166 studied the direct synthesis of ZSM-5 without calcination of kaolin.…”

NaY Zeolite Synthesis from Vermiculite and Modification with Surfactant

“…Our research group has published studies on preparing molecular sieves with alternative silica sources [15][16][17][18][19][20][21][22].…”

Valorization of solid waste (sugarcane bagasse ash) with applications in synthesis of zeolite NaA / Valorização de resíduos sólidos (cinza de bagaço de cana) com aplicações em síntese de zeólita NaA

“…Our research group has published some papers on the preparation of molecular sieve using green syntheses routes [11][12][13][14][15][16][17][18][19][20][21][22][23].…”