Developing Cu-MOR@SiO₂ Core–Shell Catalyst Microcapsules for Two-Stage Ethanol Direct Synthesis from DME and Syngas

Abstract

Catalytic conversion of Syngas and dimethyl ether to ethanol is a green strategy of harnessing fine chemicals from nonpetroleum origins. In the process, catalyst deactivation coupled with higher byproduct selectivities is still a serious cause of concern due to inevitable yield losses. Herein, we synthesized highly ordered Cu-MOR@SiO2 core–shell microcapsules, employing a facile scalable surfactant-directed sol–gel technique. Comparably, the microcapsules displayed higher DME carbonylation (83.8%) activity and a remarkable product yield (48.7%). Furthermore, confinement of Cu-MOR particles surrounded by SiO2 crystals cushions dispersed Cu components from inevitable sintering during exposure to higher temperatures, paving way for an effective regeneration treatment. However, this catalyst will function in tandem with commercialized CZA catalyst in a dual bed reactor. The novel Cu-MOR@SiO2 encapsulated catalyst displayed a stable longer service life and higher product yield, thus providing the dual bed ethanol synthesis pathway from cofeeding dimethyl ether and syngas, an opportunity toward commercial production.

Engineering of Yolk/Core–Shell Structured Nanoreactors for Thermal Hydrogenations

“…[ 72 ] Similarly, a bifunctional Cu/ZnO/γ‐Al 2 O 3 nanoreactor was reported for highly selective conversion of syngas to dimethyl ether while a core‐shell Cu‐MOR@SiO 2 nanoreactor was designed for conversion of syngas and dimethyl ether to ethanol. [ 73,74 ] This demonstrates the effectiveness of the synergistic effects achieved by proper modification of the core–shell structure. SiO 2 has been used to modify a Al 2 O 3 @Al‐supported cobalt catalyst to increase heat transfer and reduce metal–support interaction, as well as improve cobalt reduction.…”

CuZnAl@S-1 Catalyst for the Synthesis of Higher Alcohols by CO Hydrogenation

“…Excellent sintering resistance, very good selectivity, and resistance to carbon accumulation restrict mechanical damage in Cu-MOR encased by SiO 2 . Cu-MOR encapsulated in SiO 2 exhibits very good selectivity, excellent sintering resistance, and outstanding resistance to accumulation of carbon . Core–shell structured catalysts (Cu/ZnO x @Na-ZSM-5) were created by Cui et al for the selective hydrogenation of methanol from CO 2 .…”

“…Cu-MOR encapsulated in SiO 2 exhibits very good selectivity, excellent sintering resistance, and outstanding resistance to accumulation of carbon. 18 Core−shell structured catalysts (Cu/ZnO x @Na-ZSM-5) were created by Cui et al for the selective hydrogenation of methanol from CO 2 . Under the same reaction conditions, the optimal Cu/ZnO x(1.38) @Na-ZSM-5 catalyst demonstrated the highest methanol space-time yield of 44.88 g MeOH •g Cu −1 •h −1 , surpassing that of the supported Cu/ZnO x /Na-ZSM-5 catalyst and that of the industrial Cu/ZnO/Al 2 O 3 catalyst.…”

Variations in Electrochemical Characteristics of a Platinum Catalyst Enwrapped by a Carbon Shell According to Carbon Layer Thickness

“…A fuel cell is a device that directly converts the chemical energy of hydrogen into electrical energy and is thus considered to be a representative technology for hydrogen energy utilization. − However, to be widely commercialized, problems such as high price and Pt catalyst stability must be resolved. To solve the catalyst stability problem, various approaches, including an alloy catalyst, − a core–shell catalyst, − a catalyst with a protective layer such as a carbon shell, − silica layer, , and Mg oxide layer, − have been proposed. Among these, a catalyst with a carbon layer is of particular interest because it is easy to synthesize and prevents Pt dissolution and agglomeration, while maintaining adequate activity for the oxygen reduction reaction (ORR) during long-term operation.…”