Metal-stabilized radicals have been increasingly exploited in modern organic synthesis. Here, we theoretically designed a metalloradical complex Co-C˙Ph3 with the triplet characters through the transition metal cobalt (Co0) coordinating a triphenylmethyl radical. The potential catalytic role of this novel metalloradical in the CO2 reduction with H2/CH4 in the gas phase was explored via density functional theory (DFT) calculations. For the CO2 reduction reaction with H2, there are two possible pathways: one (path A) is the activation of CO2 by Co-C˙Ph3, followed by the hydrogenation of CO2. The other (path B) starts from the splitting of the H-H bond by Co-C˙Ph3, leading to the transition-metal hydride complex CoH-H, which can reduce CO2. DFT computations show that path B is more favorable than path A as their rate-determining free energy barriers are 18.3 and 27.2 kcal mol-1, respectively. However, for the reduction of CO2 by CH4 two different products, CH3COOH and HCOOCH3, can be generated following different reaction routes. Both routes begin with one CH4 molecule approaching the metalloradical Co-C˙Ph3 to form the intermediate CoH-CH3. This intermediate can evolve following two different pathways, depending on whether the H bonded to Co is transferred to the O (pathway PO) or the C (pathway PC) of CO2. Comparing their rate-determining steps, we identified that the PO route is more favorable for the reduction of CO2 by CH4 to CH3COOH with the reaction barrier 24.5 kcal mol-1. Thus, the present Co0-based metalloradical system represents a viable catalytic protocol that can contribute to the effective utilization of small molecules (H2 and CH4) to reduce CO2, and provides an alternative strategy for the exploration of CO2 conversion.
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http://dx.doi.org/10.1039/d0cp04453a | DOI Listing |
J Biol Eng
January 2025
AVT - Biochemical Engineering, RWTH Aachen University, Forckenbeckstr. 51, D-52074, Aachen, Germany.
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January 2025
School of Petroleum Engineering, Xi 'an Shiyou University, Xi'an, Shaanxi, China.
In order to determine the influence of different factors on the CO huff-and-puff displacement effect, a CO huff-and-puff experiment was carried out with Chang 6 tight sandstone samples in Ordos Basin as the research object. Combined with nuclear magnetic resonance technology, the influences of injection pressure, cycle numbers and soaking time on the CO huff-and-puff effect were evaluated, and the optimal CO huff-and-puff parameters were optimized. The microscopic degree of crude oil production in different scale pores was quantitatively characterized.
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January 2025
Prosthodontist, Implant Dentistry Associates of Arlington, Arlington, Texas, USA.
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Sci Rep
January 2025
Laboratory of Materials, Nanotechnologies and Environment, Center of Sciences of Materials, Faculty of Sciences, Mohammed V University in Rabat, Avenue Ibn Battouta, BP:1014, 10000, Rabat, Morocco.
In this study, novel polyaniline-coated perovskite nanocomposites (PANI@CoTiO and PANI@NiTiO) were synthesized using an in situ oxidative polymerization method and evaluated for the photocatalytic degradation of Rhodamine B (RhB) a persistent organic pollutant. The nanocomposites displayed significantly enhanced photocatalytic efficiency compared to pure perovskites. The 1%wt PANI@NiTiO achieved an impressive 94% degradation of RhB under visible light after 180 min, while 1wt.
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January 2025
ICAR-Indian Institute of Millets Research, Rajendranagar, Hyderabad, 500 030, Telangana, India.
The gradual increase in the consumption of mineral nitrogen is leading to heightened levels of harmful air pollutants, particularly NO emissions from the agriculture sector. A potential solution to address the issues arising from the excessive use of urea in wheat is the substitution of conventional urea with nano urea. This study aimed to quantify the effects of nano urea, both independently and in conjunction with prilled urea, under various agroclimatic and sowing conditions in India.
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