| 1. |
- Fan, Ke, et al.
(författare)
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Amorphous WO3 induced lattice distortion for a low-cost and high-efficient electrocatalyst for overall water splitting in acid
- 2020
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Ingår i: Sustainable Energy & Fuels. - : ROYAL SOC CHEMISTRY. - 2398-4902. ; 4:4, s. 1712-1722
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Tidskriftsartikel (refereegranskat)abstract
- The development of highly active and durable catalysts for water oxidation under acidic conditions is necessary but challenging for renewable energy conversion. Ir-based catalysts are highly efficient for water oxidation in acid, but their large scale application is hindered by the high cost and scarcity of iridium. Herein, we use an amorphous WO3 induced lattice distortion (AWILD) strategy to reduce the Ir content to only 2 wt% in the final material. The optimized hybrid nitrogen-doped carbon (NC)/WO3/IrO2 can efficiently catalyze water oxidation with a low overpotential of 270 mV at 10 mA cm(-2) current density (eta (10)) and a high turnover frequency of over 2 s(-1) at 300 mV overpotential in 0.5 M H2SO4, a performance that surpasses that of commercial IrO2 significantly. Introducing the layer of amorphous WO3 between IrO2 nanoparticles and NC can distort the lattice of IrO2, exposing more highly active sites for water oxidation. The AWILD effect compensates for the lower Ir content and dramatically reduces the cost of the catalyst without sacrificing the catalytic activity. Additionally, this catalyst also exhibits high activity in acid for hydrogen evolution with only 65 mV of eta (10) attributed to the AWILD effect, exhibiting efficient bifunctionality as a Janus catalyst for overall water splitting. The AWILD approach provides a novel and efficient strategy for low-cost and highly efficient electrocatalysts for acidic overall water splitting with an extremely low content of noble metals.
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| 2. |
- Jia, Yufei, et al.
(författare)
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Cu-based bimetallic electrocatalysts for CO2 reduction
- 2022
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Ingår i: Advanced Powder Materials. - : KeAi Communications Co.. - 2772-834X. ; 1:1
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Forskningsöversikt (refereegranskat)abstract
- The extensive consumption of fossil fuels has caused the rapid increase in the CO2 level in the atmosphere, forcing people to find a clean and efficient technology of CO2 conversion to alleviate CO2 emissions and develop value-added products. Among various CO2 conversion systems, electroreduction of CO2 to value-added chemicals is a feasible way for practical applications. Copper, the only metal that can catalyze CO2 reduction to multi-carbon products, has attracted the most attention among various catalysts. However, slow reaction kinetics, low product selectivity, as well as poor stability are the main drawbacks of single metallic Cu-based catalysts. Such issues can be addressed by introducing second metal in Cu-based catalysts. Here, we summarize the recent progress relating to the Cu-based bimetallic electrocatalysts for CO2 reduction, and discuss the composition and structure effects on the activity and selectivity of electrochemical CO2 reduction. Last, we outline the challenges and perspectives on electrocatalysts for this field. We expect that this review can provide new insights into the further development of Cu-based bimetallic electrocatalysts for CO2 reduction.
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| 3. |
- Shang, Yu, et al.
(författare)
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Pyrrolic N or pyridinic N : The active center of N-doped carbon for CO2 reduction
- 2022
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Ingår i: Cuihuà xuébào. - : Elsevier BV. - 0253-9837 .- 1872-2067. ; 43:9, s. 2405-2413
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Tidskriftsartikel (refereegranskat)abstract
- Pyridinic N is widely regarded as the active center while pyrrolic N has low-activity in metal-free N-doped carbon for electrocatalytic CO2 reduction reaction (CO2RR) to CO, but this viewpoint remains open to question. In this study, through density functional theoretical calculations, we first illustrate that the intrinsic activity of pyrrolic N is high enough for effectively catalyzing CO2RR, however, due to the interplay with the neighboring pyridinic N sites, the activity of pyrrolic N is dramatically suppressed. Then, experimentally, metal-free N-doped carbon spheres (NCS) electrocatalysts without significant pyridinic N content are prepared for CO2RR. The pyrrolic N in NCS shows a direct-positive correlation with the performance for CO2RR, representing the active center with high activity. The optimum NCS could produce syngas with a wide range of CO/H-2 ratio (0.09 to 12) in CO2RR depending on the applied potential, meanwhile, the best selectivity of 71% for CO can be obtained. Intentionally adding a small amount of pyridinic N to the optimum NCS dramatically decreases the activity for CO2RR, further verifying the suppressed activity of pyrrolic N sites by the neighboring pyridinic N sites. This work reveals the interaction between a variety of N species in N-doped carbon, and the potential of pyrrolic N as the new type of active site for electrocatalysts, which can improve our understanding of the electrocatalysis mechanism and be helpful for the rational design of high-efficient electrocatalysts.
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