Excitingly, evidence of cooperative catalysis is also observed when furfural, a biomass-derived aldehyde, is used as a substrate. We tested the performance of 1-nontemplated and 1-templated for the reaction between furfural and acetone, and the reaction was monitored for 16 h at 60 °C. (Scheme 1b). The results summarized in Table show that 1-templated is a more active catalyst for this reaction, achieving a conversion of 72% (1:1.5 ratio of 4:5) compared to 34% conversion (2:1 ratio of 4:5) from 1-nontemplated. Both frameworks remain crystalline, indicating that they are stable over 16 h (Fig. ). These results, combined with the apparent stability over multiple cycles, demonstrates that MOFs with co-localized Brønsted acid and base groups serve as a promising catalyst for the conversion of biomass-derived aldehydes.