Hierarchical Ti‐Beta Obtained by Simultaneous Desilication and Titanation as an Efficient Catalyst for Cyclooctene Epoxidation

Abstract

A novel post‐synthesis route to hierarchical Ti‐beta zeolite and its performance as an efficient catalyst in heterogeneous cyclooctene epoxidation are presented. Catalytically active Ti sites as well as meso‐ and macropores are simultaneously introduced into microporous beta zeolite by hydrothermal treatment by using tetrabutyl orthotitanate as the titanation agent and tetraethylammonium hydroxide as the desilication base. Simultaneous desilication and titanation (SDT) offer the advantages of reduced experimental effort and chemical waste. The possibility to use a commercial zeolite available in high quantity as the starting material is attractive for industrialization. A significant mesopore volume (Vmeso=0.19 cm3 g−1) was introduced in the resulting hierarchical Ti‐beta zeolite without loss of microporosity and crystallinity compared to the purely microporous counterpart. The comparison clearly demonstrates a higher catalytic activity for the hierarchical Ti‐beta in cyclooctene epoxidation and accelerated desorption kinetics associated with the highly interconnected pore system.

One-Step Hydrothermal Synthesis of P25 @ Few Layered MoS2 Nanosheets toward Enhanced Bi-catalytic Activities: Photocatalysis and Electrocatalysis

“…The two peaks located at 465.4 eV and 459.6 eV can be assigned to Ti 2p 1/2 and Ti 2p 3/2 , respectively, as depicted in Figure 3a. The additional peak located at 473.0 eV, which shifts about 13 eV relative to Ti 2p 3/2 , is considered as a shake-up satellite [27,28]. The O 1s XPS spectrum (shown in Figure 3b) shows four peaks that correspond to four different states of O elements.…”

State of the Art and Perspectives of Hierarchical Zeolites: Practical Overview of Synthesis Methods and Use in Catalysis

“…The first group reported no loss of microporosity and crystallinity, as well as a higher activity in the epoxidation of cyclooctene. [348] These results were also obtained by the second group who obtained an improved crystallinity and thermal stability in the synthesis of hollow beta zeolite nanocrystals. [345] Tetrapropylammonium hydroxide/ bromide (TPAOH, TPABr) was used by multiple groups, [349][350][351] as is the case for tetrabutylammonium hydroxide/bromide (TBAOH, TBABr) [352] and cetyltrimethylammonium hydroxide/bromide (CTAOH, CTABr).…”

“…[347] Similar mesoporogens with different alkyl chain-lengths (e.g., TEAOH, TPAOH, TBAOH), were used by several research groups. [345,[348][349][350][351] As such, Werner et al [348] and Morgado Prates et al [345] performed a desilication with tetraethylammonium hydroxide/bromide (TEAOH, TEABr). The first group reported no loss of microporosity and crystallinity, as well as a higher activity in the epoxidation of cyclooctene.…”

Photocatalytic Behaviors of TiO2 Nanoblets Coated with MoS2 Nanosheets for Solar‐Driven Photocatalysis

“…As shown in Figure c, the peaks at 465.2 eV and 459.5 eV are associated with Ti 2p 1/2 and Ti 2p 3/2 , respectively. The additional peak centered at 472.8 eV which shifts 13 eV relative to Ti 2p 3/2 is considered as a shake‐up satellite . Four peaks of O 1s (Figure d) indicated different states of O elements.…”