A General, Green Chemistry Approach for Immobilization of Inorganic Catalysts in Monolithic Porous Flow-Reactors

Abstract

A general, green chemistry approach is developed for the immobilization of inorganic catalysts in monolithic porous flow-reactors for continuous flow reactions, in which pyrogallol (PG) acts as an assistant layer for the in situ immobilization of various catalysts on the inner pore surface of the flow-reactor. Au nanoparticles (AuNPs), Al 2 O 3 , and phosphotungstic acid (HPW) are selected as examples of noble metals, metal oxides, and polyoxometalate (POM) type catalysts, respectively, and the corresponding flow-reactors show high catalytic performance in continuous flow hydrogenation reactions, esterification reactions, and Knoevenagel reactions, respectively. These reactions are important in the treatment of environmental contaminants and in the chemical industry. In addition, multiple monolithic flow-reactors can be assembled together for efficient performance of multi-step cascade reactions.

Mussel-Inspired Surface Engineering for Water-Remediation Materials

“…Recently, with the aid of polyphenols as an assistant layer, noble metal NPs such as Ag, Au, and Pd have been deposited on GO (Figure 16A) and boron nitride nanosheets (Figure 16B) without additional reductants. [185][186][187] The catalytic performance of the obtained nanocatalysts for 4-nitrophenol has been significantly enhanced. Polyphenols can not only act as reducing agent and stabilizer for the synthesis and immobilization of noble metal NPs (Figure 16Ca), but also reduce GO and induce the self-assembly of rGO into graphene hydrogels (Figure 16Cb), 188 which can be utilized to fabricate catalytic hydrogels with high catalytic activity and reusability for efficient reduction of methylene blue (Figure 16Cc).…”

Mesoporous ZrO2 Nanopowder Catalysts for the Synthesis of 5-Hydroxymethylfurfural

“…Hierarchically porous silica (HPS) was made according to the previous report . PEG (8.85 g) and 30 mL of TMOS were dissolved in 75 mL of acetic acid (1M).…”

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

“…Many of the products, such as 127 and its derivatives, are considered potential intermediates in the pharmaceutical industry [ 163 – 164 ], many other applications in flow have been described improving the catalyst stability. In 2016, Tao’s group developed a bioinspired metal-oxide-immobilized monolith, which was optimised for several reactions (reduction, esterification, and Knoevenagel) [ 165 ]. The authors employed a hierarchically porous silica (HPS) coated with a pyrogallol-based polyphenol film (PG).…”