Chemical Hydrogen Generation by Hierarchically Structured Quasi-ZIF-67 Catalysts with Unsaturated Metal Centers

Preparing quasi-metal–organic frameworks (Q-MOFs) with unsaturated metal sites is an effective approach for developing highly active MOF-based catalysts. In this study, we synthesized quasi-ZIF-67 (Q-ZIF-67) with large-scale structural defects via controlled thermal partial deligandation at 310 °C under an air atmosphere. This process created additional open cobalt sites and hierarchical pores within the ZIF-67 framework. The resulting Q-ZIF-67 exhibited enhanced catalytic activity for the hydrolysis of NaBH4, compared to pristine ZIF-67 and related cobalt oxide, due to a cooperative effect of Lewis acid centers and the coexistence of micro- and meso/macropores. Hydrogen was successfully generated at a rate of 18500 mL·min–1 g–1 over Q-ZIF-67 at room temperature without the need for a base and with an activation energy of 53 kJ·mol–1 under mild conditions. In addition to the catalytic performance, we investigated the kinetics and thermodynamic parameters of the hydrogen generation reaction. Our mechanistic study revealed that strong acidity is critical for efficient chemohydrogen generation of NaBH4. We confirmed this by studying the isotope effect in a D2O system, which indicated that cleavage of the O–H bond of water occurs in the rate-determining step

Application of Two Cobalt-Based Metal–Organic Frameworks as Oxidative Desulfurization Catalysts

Two new porous cobalt-based metal–organic frameworks, [Co₆(oba)₅(OH)₂(H₂O)₂(DMF)₄]_<i>n</i>·5DMF (<b>TMU-10</b>) and [Co₃(oba)₃(O) (Py)_0.5]_<i>n</i>·4DMF·Py (<b>TMU-12</b>) have been synthesized by solvothermal method using a nonlinear dicarboxylate ligand. Under mild reaction conditions, these compounds exhibited good catalytic activity and reusability in oxidative desulfurization (ODS) reaction of model oil which was prepared by dissolving dibenzothiophene (DBT) in <i>n</i>-hexane. FT-IR and Mass analysis showed that the main product of DBT oxidation is its corresponding sulfone, which was adsorbed on the surfaces of catalysts. The activation energy was obtained as 13.4 kJ/mol

A MoO₃–Metal–Organic Framework Composite as a Simultaneous Photocatalyst and Catalyst in the PODS Process of Light Oil

Photo-oxidative desulfurization (PODS) properties of MoO₃–metal–organic framework composite photocatalysts were investigated by introducing the proper weight percent of MoO₃ into a Zn­(II)-based MOF, [Zn­(oba)­(4-bpdh)_0.5]_<i>n</i>·1.5DMF (TMU-5), for the mineralization of dibenzothiophene from model oil. The addition of 3 wt % of MoO₃ into a TMU-5 host acting as a crystal growth inhibitor was confirmed by PXRD and BET results. For the first time, under mild and green reaction conditions, 5 wt % MoO₃–TMU-5 composite (MT-5) exhibited good photocatalytic activity in the model oil PODS reaction, which has no limitations in the current oxidative desulfurization catalytic systems. Only 3% of the total amount of MoO₃ content in the MT catalyst is leached during the reaction. In addition, the rate of PODS of MT-5 obeys a pseudo-first-order equation with an apparent rate constant of 0.0305 min^–1 and half-life <i>t</i>_1/2 of 22.7 min. Radical scavenger experiments and terephthalic acid fluorescence techniques confirmed that OH^<b>•</b> and O₂^{<b>•–</b>} are the main reactive species in the dibenzothiophene photocatalytic degradation. The synergic effects of the active surface of TMU-5 (organic linkers as antennas) together with the active sites of MoO₃ may lead to the further enhancement of the PODS activity of the MT-5 photocatalyst. Moreover, a possible photocatalytic desulfurization mechanism was proposed in the presence of MoO₃–TMU-5 composites

Obesity-Related Metabolomic Profiles and Discrimination of Metabolically Unhealthy Obesity

A particular subgroup of obese adults, considered as metabolically healthy obese (MHO), has a reduced risk of metabolic complications. However, the molecular basis contributing to this healthy phenotype remains unclear. The objective of this work was to identify obesity-related metabolite patterns differed between MHO and metabolically unhealthy obese (MUHO) groups and examine whether these patterns are associated with the development of cardiometabolic disorders in a sample of Iranian adult population aged 18–50 years. Valid metabolites were defined as metabolites that passed the quality control analysis of the study. In this case-control study, 104 valid metabolites of 107 MHO and 100 MUHO patients were separately compared to those of 78 normal-weight metabolically healthy (NWMH) adults. Multivariable linear regression was used to investigate all potential relations in the study. A targeted metabolomic approach using liquid chromatography coupled to triple quadrupole mass spectrometry was employed to profile plasma metabolites. The study revealed that, after Bonferroni correction, branched-chain amino-acids, tyrosine, glutamic acid, diacyl-phosphatidylcholines C32:1 and C38:3 were directly and acyl-carnitine C18:2, acyl-lysophosphatidylcholines C18:1 and C18:2, and alkyl-lysophosphatidylcholines C18.0 were inversely associated with MHO phenotype. The same patterns were observed in MUHO patients except for the acyl-carnitine and lysophosphatidylcholine profiles where acyl-carnitine C3:0 and acyl-lysophosphatidylcholine C16:1 were higher and acyl-lysophosphatidylcholines C18:1, C18:2 were lower in this phenotype. Furthermore, proline, and diacyl-phosphatidylcholines C32:2 and C34:2 were directly and serine, asparagines, and acyl-alkyl-phosphatidylcholine C34:3 were negatively linked to MUHO group. Factors composed of amino acids were directly and those containing lysophosphatidylcholines were inversely related to cardiometabolic biomarkers in both phenotypes. Interestingly, the diacyl-phosphatidylcholines-containing factor was directly associated with cardiometabolic disorders in the MUHO group. A particular pattern of amino acids and choline-containing phospholipids may aid in the identification of metabolic health among obese patients

Obesity-Related Metabolomic Profiles and Discrimination of Metabolically Unhealthy Obesity

A particular subgroup of obese adults, considered as metabolically healthy obese (MHO), has a reduced risk of metabolic complications. However, the molecular basis contributing to this healthy phenotype remains unclear. The objective of this work was to identify obesity-related metabolite patterns differed between MHO and metabolically unhealthy obese (MUHO) groups and examine whether these patterns are associated with the development of cardiometabolic disorders in a sample of Iranian adult population aged 18–50 years. Valid metabolites were defined as metabolites that passed the quality control analysis of the study. In this case-control study, 104 valid metabolites of 107 MHO and 100 MUHO patients were separately compared to those of 78 normal-weight metabolically healthy (NWMH) adults. Multivariable linear regression was used to investigate all potential relations in the study. A targeted metabolomic approach using liquid chromatography coupled to triple quadrupole mass spectrometry was employed to profile plasma metabolites. The study revealed that, after Bonferroni correction, branched-chain amino-acids, tyrosine, glutamic acid, diacyl-phosphatidylcholines C32:1 and C38:3 were directly and acyl-carnitine C18:2, acyl-lysophosphatidylcholines C18:1 and C18:2, and alkyl-lysophosphatidylcholines C18.0 were inversely associated with MHO phenotype. The same patterns were observed in MUHO patients except for the acyl-carnitine and lysophosphatidylcholine profiles where acyl-carnitine C3:0 and acyl-lysophosphatidylcholine C16:1 were higher and acyl-lysophosphatidylcholines C18:1, C18:2 were lower in this phenotype. Furthermore, proline, and diacyl-phosphatidylcholines C32:2 and C34:2 were directly and serine, asparagines, and acyl-alkyl-phosphatidylcholine C34:3 were negatively linked to MUHO group. Factors composed of amino acids were directly and those containing lysophosphatidylcholines were inversely related to cardiometabolic biomarkers in both phenotypes. Interestingly, the diacyl-phosphatidylcholines-containing factor was directly associated with cardiometabolic disorders in the MUHO group. A particular pattern of amino acids and choline-containing phospholipids may aid in the identification of metabolic health among obese patients