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The challenge of mitigating pollution stemming from industrial exhaust emissions is a pressing issue in both academia and industry. This study presents the successful synthesis of nitrogen-defect-enriched graphite carbon nitride (g-C 3 N 4 ) using a two-step calcination technique. Furthermore, a g-C 3 N 4 -Au heterostructure was fabricated through the photo-deposited Au quantum dots (QDs). When subjected to visible light irradiation, this heterostructure exhibited robust nitric oxide (NO) photooxidation activity and stability. With its fluffy, porous structure and large surface area, the nitrogen-defect-enriched g-C 3 N 4 provides more active sites for photooxidation processes. The ability of g-C 3 N 4 to absorb visible light is enhanced by the local surface plasmon resonance (LSPR) effect of Au QDs. Additionally, the lifetime of photogenerated charge carriers is extended by the presence of N defects and Au, which effectively prevent photogenerated electron-hole pairs from recombining during the photooxidation process. Moreover, the oxidation pathway of NO was analyzed through In-situ Fourier transform infrared (FT-IR) spectroscopy and Density Functional Theory (DFT) calculation. Computational findings revealed that the introduction of Au QDs decreases the activation energy of the oxidation reaction, thereby facilitating its occurrence while diminishing the formation of intermediate products. As a result, NO is predominantly converted to nitrate (NO 3 - ). This work unveils a novel approach to constructing semiconductor-cocatalyst heterostructures and elucidates their role in NO photooxidation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The potassium and proton mixed salt of mono-Nb substituted Keggin-type phosphomolybdate, KH 3 [PMo 11 NbO 40 ], was isolated in a pure form by reacting Keggin-type phosphomolybdic acid (H 3 [PMo 12 O 40 ]) and potassium hexaniobate (K 8 Nb 6 O 19 ) in water, followed by freeze-drying. The all protonic form, H 4 [PMo 11 NbO 40 ], was isolated via proton exchange with H-resin and subsequent freeze-drying. The most crucial factor to isolate KH 3 [PMo 11 NbO 40 ] and H 4 [PMo 11 NbO 40 ] in pure forms is the evaporation of water using the freeze-drying method. Using a similar procedure, the potassium salt of the di-Nb substituted compound K 5 [PMo 10 Nb 2 O 40 ] was isolated. H 4 [PMo 11 NbO 40 ] exhibited high catalytic activity for oxidizing isobutylaldehyde to methacrolein and moderate catalytic activity for the Wacker-type oxidation of allyl phenyl ether when combined with Pd(OAc) 2 .

Glycerol valorization through partial oxidation is a good way of obtaining many different molecules with high added value such as glyceric acid, tartronic acid, dihydroxyacetone, etc. Among the potential products, glyceraldehyde is an interesting chemical compound for its various applications in different domains such as organic chemistry, medical, and cosmetic industries. In the present paper, we studied the effect of different supports on the glycerol oxidation reaction in a batch reactor applying base-free conditions. The tested catalysts were Pt-based materials deposited on various supports (i.e., SiO 2 , TiO 2 , ZSM-5, γ-Al 2 O 3 ), which were synthesized using a deposition method followed by a chemical reduction. The catalysts were extensively characterized (BET, ICP, XRD, TEM, XPS), highlighting differences in terms of specific surface areas, textural properties, and Pt nanoparticles sizes. We evidenced a direct relation between glycerol conversion and glyceraldehyde selectivity (i.e., an increase in glycerol conversion leads to a decrease in glyceraldehyde selectivity). The Pt/γ-Al 2 O 3 catalysts exhibited the highest activity, but their selectivity to glyceraldehyde significantly decreased with time on stream. Pt/SiO 2 presented the highest selectivity to glyceraldehyde owing to a slower reaction rate, which allows envisioning technical opportunities to continuously extract the formed glyceraldehyde from the mixture.