A methodology is introduced for controlled postsynthetic thermal defect engineering (TDE) of precious group metal–organic frameworks (PGM-MOFs). The case study is based on the Ru/Rh analogues of the archetypical structure [Cu3(BTC)2] (HKUST-1; BTC = 1,3,5-benzenetricarboxylate). Quantitative monitoring of the TDE process and extensive characterization of the samples employing a complementary set of analytical and spectroscopic techniques reveal that the compositionally very complex TDE-MOF materials result from the elimination and/or fragmentation of ancillary ligands and/or linkers. TDE involves the preferential secession of acetate ligands, intrinsically introduced via coordination modulation during synthesis, and the gradual decarboxylation of ligator sites of the framework linker BTC. Both processes lead to modified Ru/Rh paddlewheel nodes. These nodes exhibit a lowered average oxidation state and more accessible open metal centers, as deduced from surface-ligand IR spectroscopy using CO as a probe and supported by density functional theory (DFT)-based computations. The monometallic and the mixed-metal PGM-MOFs systematically differ in their TDE properties and, in particular in the hydride generation ability (HGA). This latter property is an important indicator for the catalytic activity of PGM-MOFs, as demonstrated by the ethylene dimerization reaction to 1-butene.

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In this work novel nickel catalysts based on nickel aluminate deposited on ceria-based supports (CeO 2 and Ce 0.13 Zr 0.87 O 2 ) were investigated for the partial oxidation of methane. The good catalytic behavior of the CeO 2 -based sample under moderate (38400 mL of CH 4 g −1 h −1 and stoichiometric feed) and severe (60000 mL of CH 4 g −1 h −1 , an O/C molar ratio of 0.8, and prolonged time on stream (30 h)) reaction conditions was mainly assigned to the small particle size (about 10 nm) that was achieved after the hightemperature reduction of the spinel and its notable redox properties. CeAlO 3 formation was found to have a negative effect on the catalytic performance, which was more pronounced for the Ce 0.13 Zr 0.87 O 2 -supported catalyst. This negative impact could be controlled by the introduction of La 2 O 3 since this promoter reacted with alumina to give LaAlO 3 instead of CeAlO 3 and favored carbon gasification in the vicinity of nickel particles.