Metal-organic frameworks (MOFs) are porous crystalline materials with record surface areas that have proven useful as heterogeneous supports for nanocatalysts. Interestingly, the confined environment of a MOF’s pore can sometimes lead to surprising reactivity and selectivity. However, the vast majority of reports focused on MOFs in catalysis are limited to “proof-of-concept” studies performed in small scale with model substrates. We report the development of robust catalytic processes based on Pd nanoparticles supported in the pores of various robust MOFs and demonstrate their applicability in commercially relevant processes. For example, our materials were adapted for microflow packed-bed reactors and libraries of complex molecules, relevant as active pharmaceutical intermediates, could be obtained via cross-coupling reactions under a continuous flow regime, without changing the catalyst. Further, we describe methods of improving the endurance of soft MOF crystals to thermal and chemical stress by reinforcing them with a protective porous silica coating. This treatment leads to a material that can withstand more than one week of continuous flow operation at 110 °C, under oxidative conditions, without any signs of deactivation. In batch, the same reinforced catalyst is shown to be remarkably easy to recycle even at 150 °C by using a “teabag” procedure developed in our group.[ii] Finally, we also report on the ability of our catalysts to promote selective C–H functionalization reactions[iii] and a selective reduction of C=C double bonds in the presence of other reducible groups, for challenging molecules of commercial interest. The transformations suffered by the Pd@MOF materials throughout these processes are monitored by in-situ XAS methods, which offer valuable insights into the nature of the real active species. ChemSusChem, 2015, 8, 123 – 130. [ii] ACS Catal., 2015, 5, 472 – 479. [iii] Chem. Eur. J., 2015, DOI: 10.1002/chem.201502918.

Development of MOF supported catalysts for commercially relevant processes

251st National Meeting (2016)

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