We report a facile synthetic protocol to prepare mesoporous FeS without the aid of hard template as an electrocatalyst for the hydrogen evolution reaction (HER). The mesoporous FeS materials with high surface area were successfully prepared by a sol-gel method following a sulfurization treatment in an HS atmosphere. A remarkable HER catalytic performance was achieved with a low overpotential of 96 mV at a current density of 10 mA·cm and a Tafel slope of 78 mV per decade under alkaline conditions (pH 13). The theoretical calculations indicate that the excellent catalytic activity of mesoporous FeS is attributed to the exposed (210) facets. The mesoporous FeS material might be a promising alternative to the Pt-based electrocatalysts for water splitting.

A recent report from the United Nations has warned about the excessive CO2 emissions and the necessity of making efforts to keep the increase in global temperature below 2 °C. Current CO2 capture technologies are inadequate for reaching that goal, and effective mitigation strategies must be pursued. In this work, we summarize trends in materials development for CO2 adsorption with focus on recent studies. We put adsorbent materials into four main groups: (I) carbon-based materials, (II) silica/alumina/zeolites, (III) porous crystalline solids, and (IV) metal oxides. Trends in computational investigations along with experimental findings are covered to find promising candidates in light of practical challenges imposed by process economics.

Selective oxidation of amines to imines is one of the most studied reactions in the field of heterogeneous catalysis. Cs ion promoted mesoporous manganese oxide (meso Cs/MnO x ) was synthesized using inverse surfactant micelle as a soft template. The chemical and structural properties of the mesoporous manganese oxide material were characterized by powder X-ray diffraction (PXRD), nitrogen sorption, electron microscopy and X-ray photoelectron spectra (XPS). The meso-Cs/MnO x material presented aggregated nanocrystalline nature with monomodal mesoporous size distributions. The catalyst was found to be effective in oxidation of amines to imines under aerobic conditions. The meso Cs/MnO x exhibited oxidation of primary, secondary, cyclic, aromatic, and aliphatic amines to imines, where the conversions reached as high as >99%. The catalyst was also effective in oxidative cross condensation of two different amines to produce asymmetrically substituted imines. Surface active Mn 3+ species along with labile lattice oxygen were found to play an important role in the catalytic activity. Mild reaction conditions (air atmosphere and absence of any oxidative or basic promoters), ease of product separation by simple filtration and significant reusability make this mesoporous manganese oxide material an economical and ecofriendly catalyst for the syntheses of versatile imine derivatives.

We report a preparation method for visible light responsive Carbon Quantum Dots (CQDs) embedded in mesoporous TiO 2 materials. The as-prepared mesoporous TiO 2 (meso-Ti-450) material is a member of the recently designed University of Connecticut (UCT) mesoporous materials family. The UCT materials were synthesized based on sol-gel chemistry. The nanoparticles are randomly packed in inverse surfactant micelles and mesopores are formed by interconnected intraparticles. To achieve full usage of the visible region of sunlight (> 400 nm), CQDs were introduced without destroying the mesopores. The photocatalytic performance of the CQDs/meso-Ti-450 was investigated by the degradation of methylene blue. Due to the up-conversion property and electron withdrawing property of CQDs, the photocatalytic activity of the composite material was largely enhanced under visible light irradiation. The highest photocatalytic activity was achieved by 5% CQDs/meso-Ti-450 in an hour. Compared to commercial P25, which is capable of removing 10% methylene blue (MB) under visible light conditions, the 5% CQDs/meso-Ti-450 can mostly remove MB (98%) under the same conditions. To date, the usage of mesoporous titanium oxide and carbon material composites for dye degradation under visible light has not been reported.

Herein we introduce an environmentally friendly approach to the synthesis of symmetrical and asymmetrical aromatic azo compounds by using air as the sole oxidant under mild reaction conditions in the presence of cost-effective and reusable mesoporous manganese oxide materials.

Electrocatalysis of water is a scalable and easily available source of the production of hydrogen (H2), the future energy carrier. This drive for clean energy inspired us to develop an inexpensive, readily producible, highly active, and stable catalyst to replace current state of the art platinum catalysts. Building on the promising hydrogen evolution reaction (HER) activity of many pyrites, their structural tuning by different metals and nonmetals has been found to be effective in several instances. We present here one such effort by partial surface selenization of mesoporous cobalt sulfide material, which displayed long-term operational stability (for at least 25 h) besides attaining a current density of 100 mA cm–2 at an overpotential of 160 mV versus the reversible hydrogen electrode (RHE) (in acidic media). A low Tafel slope (of 52 mV dec–1) and high exchange current density (j 0) (of 70 μA cm–2) make our catalyst better to most existing systems. More importantly, using a variety of analytical techniques, electrochemical measurements, and theoretical calculations, we have analyzed the morphology of the material and rationalized the key to the enhanced intrinsic activity (as compared to the meso-CoS2) per active site. This study is expected to explain similar systems and modify approaches to enhancing the electrochemical activity of metal chalcogenides.

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We report a heterogeneous catalytic protocol for the oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) using a mesoporous manganese doped cobalt oxide material. The absence of precious metals and additives, use of air as the sole oxidant, and easy isolation of products, along with proper catalyst reusability, make our catalytic protocol attractive for the selective oxidation of HMF to DFF.