Two-Step Hydrothermal Synthesis of Submicrometric and Hierarchical Hollow SAPO-34 with Superior Catalytic Performance in Methanol to Olefin (MTO) Reaction

A submicrometric and hierarchical hollow SAPO-34 molecular sieve was synthesized by an easy and low-cost two-step hydrothermal method. First, the crystallized mixture was obtained by direct drying after a first-step hydrothermal reaction. Then, the SAPO-34 product was obtained by adding the crystallized mixture to silicon-free gel and using cheap and common template agents. Compared to conventional SAPO-34, the submicrometric and hierarchical hollow SAPO-34 exhibits superior catalytic activity in the MTO reaction.

The hydrothermal synthesis of hierarchical SAPO-34 with improved MTO performance

A two-step hydrothermal approach for the synthesis of hierarchical SAPO-34 in the absence of any mesoporogen.

Recent Progress in Methanol-to-Olefins (MTO) Catalysts

Methanol conversion to olefins, as an important reaction in C1 chemistry, provides an alternative platform for producing basic chemicals from nonpetroleum resources such as natural gas and coal. Methanol-to-olefin (MTO) catalysis is one of the critical constraints for the process development, determining the reactor design, and the profitability of the process. After the construction and commissioning of the world's first MTO plant by Dalian Institute of Chemical Physics, based on high-efficiency catalyst and fluidization technology in 2010, more attention has been attracted for a deep understanding of the reaction mechanism and catalysis principle, which has led to the continuous development of catalysts and processes. Herein, the recent progress in MTO catalyst development is summarized, focusing on the advances in the optimization of SAPO-34 catalysts, together with the development efforts on catalysts with preferential ethylene or propylene selectivity.

A phase-transfer crystallization pathway to synthesize ultrasmall silicoaluminophosphate for enhanced catalytic conversion of dimethylether-to-olefin

This work reports a new phase-transfer crystallization pathway to generate ultrasmall silicoaluminophosphate SAPO-34 for enhanced catalytic dimethylether-to-olefin conversion.

Performance Enhanced SAPO-34 Catalyst for Methanol to Olefins: Template Synthesis Using a CO2-Based Polyurea

Introducing mesopores into the channels and cages of conventional micropores CHA (Chabazite) topological structure SAPO-34 molecular sieves can effectively improve mass transport, retard coke deposition rate and enhance the catalytic performance for methanol to olefins (MTO) reaction, especially lifetime and olefins selectivity. In order to overcome the intrinsic diffusion limitation, a novel CO2-based polyurea copolymer with affluent amine group, ether segment and carbonyl group has been firstly applied to the synthesis of SAPO-34 zeolite under hydrothermal conditions. The as-synthesized micro-mesoporosity SAPO-34 molecular sieve catalysts show heterogeneous size distribution mesopores and exhibit slightly decrease of BET surface area due to the formation of defects and voids. Meanwhile, the catalysts exhibit superior catalytic performance in the MTO reaction with more than twice prolonged catalytic lifespan and improvement of selectivity for light olefins compared with conventional microporous SAPO-34. The methodology provides a new way to synthesize and control the structure of SAPO-34 catalysts.

A facile organosilane-based strategy for direct synthesis of thin MWW-type titanosilicate with high catalytic oxidation performance

A facile organosilane-based synthetic strategy was successfully developed to prepare thin Ti-MWW zeolite with high catalytic oxidation performance.

Cost-effective synthesis of hierarchical SAPO-34 zeolites with abundant intracrystalline mesopores and excellent MTO performance

Hierarchical SAPO-34 catalysts with abundant intracrystalline mesopores have been cost-effectively synthesized showing remarkably enhanced performance in methanol-to-olefin reactions.

Nanoseed-assisted synthesis of nano-sized SAPO-34 zeolites using morpholine as the sole template with superior MTO performance

Nano-sized SAPO-34 catalysts have been prepared using morpholine as the sole template via a nanoseed-assisted method showing superior MTO performance.