Biodiesel, a renewable bio-based transport fuel consisting of alkyl esters of long-chain fatty acids, is gaining attention as an alternative to non-renewable petroleum diesel. We prepared adjustable interlayer spacing urea-crosslinked 3D graphene oxide/MXene-SO 3 /cyclodextrin (MGUC) film to achieve efficient and sustainable biodiesel production. Ti 3 C 2 T X (MXene) grafted sulfonic acid groups as acid-catalytic sites of the film with graphene oxide (GO) via urea cross-linking and doping cyclodextrin (CD) to construct multistage pore structures (internal pore structures generated by urea cross-linking as well as CD host-guest structures) synergistically catalyzed biodiesel production. Meanwhile, the heterogeneous carbon-based materials based on GO and MXene-S have excellent photothermal efficiency, which can achieve 95.6 % biodiesel conversion at 4 h and maintain 75.32 % activity after 8 cycles. We verified the reason for the high catalytic activity of the MGUC films, which rationalized the fast mass transfer mechanism of CD by Density functional theory (DFT)and verified the transport mechanism of the heterojunction for efficient photothermal. Therefore, this CD carbon-based solid acid film catalytic platform provides a new direction for the green and efficient preparation of bioenergy.
The rule of equilibrium governs reversible chemical reactions, including the industrial manufacture of esters. To boost an esterification reaction’s conversion, it is common to change the ratio of reactants or dehydrating agents to drive the reaction. However, these methods can add difficulties to the separation of the final products. Therefore, we prepared a photothermal-catalytic systems of a class of ‘cell-structured’ MXene-SO 3 /GO/CD (MGC) aerogels by modifying the sulfonic acid group on MXene as a catalytic site, graphene oxide (GO) as a framework and cyclodextrins (CD) dispersed in heterojunctions to enhance the pore size and specific surface area, through localized photothermal heating and different molecular bonding affinities to evaporate the reaction product (catalytic site MXene-S has a lower binding energy-24.76 kcal/mol to the product). Therefore leads to a localized excess of the reactant, thus thermodynamically driving the reaction in a positive direction. We verified the catalytic mechanism by calculating the ethyl acetate yield by 1 H NMR and combining it with DFT to calculate the binding energies of the catalytic sites and the reactants to the products. Under the strong photothermal conditions, the MGC catalyzed the conversion of ethyl acetate up to 79 %, and the catalytic conversion only slightly decreased within 120 h due to the good stability and recyclability of the aerogel. This study not only provides design ideas for the preparation of heterogeneous hybrid aerogels with high photothermal conversion, but also provides new ideas for the design of reversible chemical equilibria in industry.
危险品化学品经营许可证（带存储）