Ordered Mesoporous Carbon Encapsulating KF: Efficient and Stable Solid Base for Biodiesel and Fine Chemical Catalytic Synthesis

Abstract

Developing efficient and reusable catalysts to transform raw feedstocks into high value-added fine chemicals and biofuels has received considerable research interest. Herein, we report ordered mesoporous carbon (OMC) encapsulating KF to design novel chainmail solid base catalysts (KF@OMC-x, where x stands for the weight ratio of potassium). The OMC armor can be facilely prepared from a one-step mechanochemical synthesis without the assistance of any solvents, which was achieved from the grinding of resorcinol, terephthalaldehyde, and block copolymer template (Pluronic F127, PEO106–PPO70–PEO106), solidothermal treatment at 150 °C, and calcined at 360 °C for the removal of the template. The obtained OMC was then impregnated with the KF precursor and annealed at 500 °C to reinforce the interaction, and the KF superbase site can be encapsulated into the OMC armor. The resultant KF@OMC-x possess characteristics including large BET surface areas (351–445 m2/g), long-range ordered mesoporosity with narrow pore sizes (∼6.0 nm), and good dispersion of KF superbase sites with an enhanced stability. Consequently, KF@OMC-x can be employed as high-efficient and reusable catalysts in base-catalyzed liquid reactions including toward transesterification to biodiesel and Knoevenagel condensation to fine chemicals. Their activities were even better than widely used strong base catalysts such as KF, Na2CO3, CaO, and hydrotalcite. This study may help to develop effective and stable solid base catalysts for the scalable production of biofuels under harsh industrial processes.

Engineering NH2‐Cu‐NH2 Triple‐atom Sites in Defective MOFs for Selective Overall Photoreduction of CO2 into CH3COCH3

“…No Cu−Cu coordination of the Cu foil was found (Figure 1e), further revealing the isolated dispersion of Cu single atoms without aggregation into particles [21] . N 2 adsorption‐desorption isotherms (Figures S14–S15) showed that the BET surface area of the Cu‐MOF was lower than that of d‐MOF (788 vs. 1063 m 2 g −1 ), but their pore size distributions were similar, indicating that Cu ions combine with UiO‐66‐NH 2 defects (d‐MOF) and may partially occupy the pores of MOF [23] …”

Recent advances in supported acid/base ionic liquids as catalysts for biodiesel production

“…Encapsulation is a novel strategy for heterogeneous ILs, where active species are physically accommodated in highly porous materials ( Zheng et al, 2022 ). Compared with the immobilization method in which the active sites of the catalyst are fixed on the support, the active sites of the catalyst synthesized by the encapsulation strategy are flowable and free, which can promote the activity of the catalyst ( Kong et al, 2016 ).…”

Sustainable Porous Heterogeneous Catalysts for the Conversion of Biomass into Renewable Energy Products

“…A variety of solid catalysts have been used in biomass conversion to desired fuels and commodity chemicals over the past 3-4 decades. As a consequence, several articles have been published highlighting the production of bio-based fuels and valuable chemicals, which are mostly focused on different conversion pathways. − However, the catalytic behavior of recyclable heterogeneous porous nanomaterials still needs to be explored for the upgradation in the biomass conversion processes. The past decades have witnessed utilization of solid acid catalysts, as they exhibited stimulating catalytic activity and selectivity with superior reusability. , In this regard, the nanoporous catalysts have an advantage due to their large accessible surface-active sites, pore tunability, and easily adjustable surface wettability, which effectively controls the product selectivity, adsorption, and diffusion of incoming bio-based oxygenated feedstocks.…”