Fig. 6. Diels–Alder cycloaddition–dehydration reactions of DMFDC catalyzed by CIT-6 and CIT-6-re-Zn-pH = 6.9 at various temperatures. Resulting yields (%) of DMT, MF, MB, CHO, and DMFDC are calculated as ratio of moles formed to initial moles of DMFDC. Mass on catalyst (%) is expressed as ratio of combustible mass on catalyst (measured by TGA) to initial mass of DMFDC. Reaction conditions: 12 h, effective concentration of 0.033 M DMFDC in 10 mL heptane, 100 mg of catalyst, and 35 bar C₂H₂ at 25 °C.