A CuO−ZnO−Al2O3−ZrO2 + HZSM-5 physical mixture bifunctional catalyst with a high activity for dimethy ether (DME) synthesis was used for CO2 hydrogenation. Various factors that affect catalyst activity, including the reaction temperature, pressure, and space velocity, were investigated. CO2 conversion reached 0.309, and DME and methanol yields were 0.212 and 0.059 with a stoichiometric ratio of H2 to CO2 of 3 at 523 K, 5 MPa, and a space velocity of 6000 mL/(g cat·h). Well-studied kinetic models for methanol synthesis and methanol dehydration, respectively, were used to fit the experimental data and the kinetic parameters in the rate equations for DME synthesis were obtained by regression. A simulated process for CO2 hydrogenation indicated that a higher DME yield can be obtained with CO recycle that will also give a CO-free product.

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A series of Cu/Zn/Al/Zr CO 2 hydrogenation to methanol catalysts containing different ratios of Al/Zr were prepared using a co-precipitation procedure. SEM, TEM, and XRD characterization showed that all the catalysts comprised crystallites in a fibrous structure and their Cu/Zn crystallite dispersions were better than that of a commercial (COM) catalyst. It is suggested that the high dispersion and stability of the Cu/Zn crystallites due to the fibrous structure enhanced CO 2 hydrogenation, and the added Zr component further improved the catalyst. A 5% Zr addition gave a methanol space time yield 80% higher than that on the COM catalyst.

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A novel Ru(II) complex, [Ru(bpy)2(DNPS-bpy)](PF6)2 (bpy: 2,2'-bipyridine, DNPS-bpy: 4-(2,4-dinitrophenylthio)methylene-4'-methyl-2,2'-bipyridine), has been designed and synthesized as a highly sensitive and selective luminescence probe for the recognition and detection of hypochlorous acid (HOCl) in living cells by exploiting a "signaling moiety-recognition linker-quencher" sandwich approach. The complex possesses large stokes shift (170 nm), long emission wavelength (626 nm), and low cytotoxicity. Owing to the effective photoinduced electron transfer (PET) from Ru(II) center to the electron acceptor, 2,4-dinitrophenyl (DNP), the red-emission of bipyridine-Ru(II) complex was completely withheld. In aqueous media, HOCl can trigger an oxidation reaction to cleave the DNP moiety from the Ru(II) complex, which results in the formation of a highly luminescent bipyridine-Ru(II) complex derivative, [Ru(bpy)2(COOH-bpy)](PF6)2 (COOH-bpy: 4'-methyl-2,2'-bipyridyl-4-carboxylic acid), accompanied by a 190-fold luminescence enhancement. Cell imaging experimental results demonstrated that [Ru(bpy)2(DNPS-bpy)](PF6)2 is membrane permeable, and can be applied for capturing and visualizing the exogenous/endogenous HOCl molecules in living cell samples. The development of this Ru(II) complex probe not only provides a useful tool for monitoring HOCl in living systems, but also strengthens the application of transition metal complex-based luminescent probes for bioimaging.

Oxidative desulfurization (ODS) plays critical roles in the production of high-quality sulfur impurity-free fuels, especially procedures using molecular oxygen as the sole oxidant. However, the state-of-the-art systems still rely on noble metal nanocatalysts, with deactivation issues caused by coking and sintering still present. Herein, leveraging the merits of single-atom catalysts (SACs) with earth-abundant metal cores and robust nanoporous supports, a series of catalysts composed of homogeneously distributed single chromium atoms anchored on multiwalled carbon nanotubes were fabricated and deployed to catalyze the aerobic ODS transformation. Adopting aromatic sulfur compound (ASC)-containing alkanes as a model system with molecular oxygen as the oxidant, efficient oxygen-to-active O2 •– transformation and subsequent ASCs-to-sulfone conversion have been achieved, with the former benefiting from the chromium-active sites and the latter arising from the robust, nanoporous, and π-conjugated architecture of the supports. The attractive catalytic performance and cycling stability of the chromium-based SACs make them promising candidates in practical sulfur species removal from liquid fuels, supplying an alternative guidance on the catalyst design toward cost-effective and energy-efficient ODS procedures.

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