This study employs a low-field NMR (LF-NMR) method to investigate Cr(VI) adsorption and reduction in solid-liquid systems, focusing on three cellulose-based amine adsorbents. NMR revealed the effects of molecular structure on adsorption and reduction processes, providing insights into adsorbent design and mass transfer advantages for high-performance Cr(VI) adsorbents.
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http://dx.doi.org/10.1039/d4cc05714g | DOI Listing |
Langmuir
January 2025
Centre for Energy (M473), The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
The mechanisms of NO reduction by CO over nitrogen-doped graphene (N-graphene)-supported single-atom Ni catalysts in the presence of O, HO, CO, and SO have been studied via density functional theory (DFT) modeling. The catalyst is represented by a single Ni atom bonded to four N atoms on N-graphene. Several alternative reaction pathways, including adsorption of NO on the Ni site, direct reduction of NO by CO, decomposition of NO to NO followed by reduction of NO to N, formation of active oxygen radical O*, and reduction of O* by CO, were hypothesized and the energy barrier corresponding to each of the reaction steps was calculated using DFT.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry and Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China.
Single-atom catalysts (SACs) have attracted widespread attention due to their potential to replace platinum-based catalysts in achieving efficient oxygen reduction reaction (ORR), yet the rational optimization of SACs remains challenging due to their elusive reaction mechanisms. Herein, by employing ab initio molecular dynamics simulations and a thermodynamic integration method, we have constructed the potential-dependent free energetics of ORR on a single iron atom catalyst dispersed on nitrogen-doped graphene (Fe-N/C) and further integrated these parameters into a microkinetic model. We demonstrate that the rate-determining step (RDS) of the ORR on SACs is potential-dependent rather than invariant within the operative potential range.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Physics Department & Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, North Zhongshan Road 3663, Shanghai 200062, P. R. China.
This study employs a low-field NMR (LF-NMR) method to investigate Cr(VI) adsorption and reduction in solid-liquid systems, focusing on three cellulose-based amine adsorbents. NMR revealed the effects of molecular structure on adsorption and reduction processes, providing insights into adsorbent design and mass transfer advantages for high-performance Cr(VI) adsorbents.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Department of Chemical Engineering, Northeastern University, Boston, Massachusetts, 02115, USA.
Discovering electrocatalysts that can efficiently convert carbon dioxide (CO) to valuable fuels and feedstocks using excess renewable electricity is an emergent carbon-neutral technology. A single metal atom embedded in doped graphene, , single-atom catalyst (SAC), possesses high activity and selectivity for electrochemical CO reduction (COR) to CO, yet further reduction to hydrocarbons is challenging. Here, using density functional theory calculations, we investigate stability and reactivity of a broad SAC chemical space with various metal centers (3d transition metals) and dopants (2p dopants of B, N, O; 3p dopants of P, S) as electrocatalysts for COR to methane and methanol.
View Article and Find Full Text PDFSmall
January 2025
Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, Delhi, 110016, India.
Crystalline γ-FeO(OH) dominantly possessing ─OH terminals (𝛾-FeO(OH)), polycrystalline γ-FeO(OH) containing multiple ─O, ─OH, and Fe terminals (𝛾-FeO(OH)), and α-FeO majorly containing ─O surface terminals are used as electrocatalysts to study the effect of surface terminals on electrocatalytic nitrate reduction reaction (eNORR) selectivity and stabilization of reaction intermediates. Brunauer-Emmett-Teller analysis and electrochemically determined surface area suggest a high active surface area of 117.79 m g (ECSA: 0.
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