Tin-carboxylate MOFs for sugar transformation into methyl lactate

Abstract

With the purpose of improving the production of methyl lactate (ML) from sugars (glucose and sucrose), a new metal‐organic framework (MOF) denoted as UZAR‐S10, containing Sn ions and ligand 2‐aminobenzene‐1,4‐dicarboxylate was synthesized. The SEM and PXRD characterization revealed that UZAR‐S10 was highly crystalline. The empirical formula of UZAR‐S10 is [(NH2‐BDC)Sn]·(NH2‐BDC)0.5, i.e., per Sn atom, with one structural ligand molecule and half ligand molecule trapped in the MOF structure. The removal of the trapped ligand by either solvent extraction or thermal treatment damaged the structure of UZAR‐S10, not enabling its activation. The performance of UZAR‐S10 in the production of ML was compared to those achieved with different types of carboxylate MOFs, especially with that of Sn partially substituted Ti tetracarboxylate MOF denoted MIP‐177‐LT (MIP‐177‐LT(Ti/Sn)). The highest ML yields achieved from sucrose were 29.5 % and 42.0 % for UZAR‐S10 and MIP‐177‐LT(Ti/Sn), respectively. For comparison, other carboxylate type MOFs (MIL‐53(Al), NH2‐MIL‐53(Al), UiO‐66, MIL‐101(Cr) and HKUST‐1) were tested at the same conditions with worse performance than the two Tin‐containing MOFs.