The catalytic cracking of sterically challenging plastic feedstocks over high acid density Al-SBA-15 catalysts

Abstract

Highlights  Synthesis of Al-SBA-15 catalysts with similar acidic properties to zeolites.  Al-SBA-15 catalysts overcomes diffusional limitations of ZSM-5 in LDPE cracking.  Aluminium rich SBA-15 exhibits high selectivity to gasoline range hydrocarbons.  Selectivity can be fine-tuned by controlling the incorporation of Al into SBA-15.

The role of catalyst acidity and shape selectivity on products from the catalytic fast pyrolysis of beech wood

“…into the silica structure of the SBA-15 results in loss of microporosity, leading to a substantially mesoporous structure as evidenced by the type H1 hysteresis loop in the raw isotherm [42]. In turn, this results in lower total surface areas, in agreement with what was observed for the Al-SBA-15 catalyst in this work.…”

Induction Heating in Nanoparticle Impregnated Zeolite

“…However, their microporous nature also presents some limitations, especially in what concerns mass transfer limitations of bulky molecules inside the pores [9]. These constraints can be reduced through the use of mesoporous structures with acidic character or hierarchical zeolites exhibiting both micro and mesoporosity [10,11]. Among the various types of zeolite structures (ex: H-ZSM-5, H-MOR, H-FER), H-USY zeolite stands out for its greater accessibility.…”

Cellulose Conversion to 5 Hydroxymethyl Furfural (5-HMF) Using Al-Incorporated SBA-15 as Highly Efficient Catalyst

“…e cellulose conversion is strongly depended on the acidity of the catalysts. To determine the acidity of Al incorporated SBA-15, we used the NH 3 -TPD method [14]. Figure 5 shows NH 3 -TPD profiles of Al incorporated SBA-15.…”

“…As a result, it normally plays a role of adsorbent, not acidic or redox catalysts [7,8]. In order to be used as acidic or redox catalysts, SBA-15 should be modified by incorporation of transition metals into framework using direct and/or postsynthesis [9][10][11][12][13][14][15][16][17]. Aluminium ions (Al 3+ ) insertion into the SBA-15 creates acid sites in the structure which is extremely important for acid-catalyzed reaction.…”

“…However, the incorporation of aluminium into Al/SBA-15 is difficult because of the difference in hydrolysis rates of Al and Si in low pH medium during the SBA-15 synthesis process [18]. Various synthetic methods have been devoted for the incorporation of higher amounts of aluminium to achieve higher acid sites [14,16,17].…”