A Comparative Study of Y Zeolite Catalysts Derived from Natural and Commercial Silica: Synthesis, Characterization, and Catalytic Performance.

Saleh, Najat J.; Al-Zaidi, Bashir Y. Sherhan; Sabbar, Zainab M.

Hydrothermal synthesis process of the zeolite type Y and production of different forms (i.e., NaY, NH4Y<inline-graphic></inline-graphic>, and HY) were accomplished. Both natural silica nanoparticles derived from rice husk (RH) and commercial Ludox as a source of silica were applied for preparing a number of type NaY zeolite catalysts. The aim of this study was to investigate the effects of adding different weight percentages of natural and/or commercial silica into either seed gel or feedstock gel on the synthesis, characterization, and catalytic performance of Y zeolite. A high purity of nanosilica (about 98.9 wt%) was generated using the precipitation method, followed by burning to reduce the metallic ingredients from rice husk ash (RHA). The thermal behavior of the RH was investigated by TGA, while the composition of nanosilica and the chemical analysis of RHA after acid treatment were analyzed by XRF. In addition, the properties of catalysts were characterized using XRD, BET, SEM, EDX, AAS, and FTIR. The catalytic activity and selectivity of prepared Y catalysts were studied using the laboratory-scale fixed-bed catalytic cracking unit throughout the C6H14<inline-graphic></inline-graphic> cracking reaction at 450 ∘C<inline-graphic></inline-graphic>. The results indicate significant enhancements in the catalytic performance of the produced nanosilica catalyst created by adding only natural silica in both feedstock gel and seed gel for the preparation of overall Y zeolite gel.

ZEOLITE catalysts; SILICA; HYDROTHERMAL synthesis

Arabian Journal for Science & Engineering (Springer Science & Business Media B.V. ), 2018, Vol 43, Issue 11, p5819

2193-567X

Academic Journal

10.1007/s13369-017-3014-0