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Herein, an effective tandem catalysis strategy is developed to improve the selectivity of the CO2RR towards C2H4 by multiple distinct catalytic sites in local vicinity. An earth‐abundant elements‐based tandem electrocatalyst PTF(Ni)/Cu is constructed by uniformly dispersing Cu nanoparticles (NPs) on the porphyrinic triazine framework anchored with atomically isolated nickel–nitrogen sites (PTF(Ni)) for the enhanced CO2RR to produce C2H4. The Faradaic efficiency of C2H4 reaches 57.3 % at −1.1 V versus the reversible hydrogen electrode (RHE), which is about 6 times higher than the non‐tandem catalyst PTF/Cu, which produces CH4 as the major carbon product. The operando infrared spectroscopy and theoretic density functional theory (DFT) calculations reveal that the local high concentration of CO generated by PTF(Ni) sites can facilitate the C−C coupling to form C2H4 on the nearby Cu NP sites. The work offers an effective avenue to design electrocatalysts for the highly selective CO2RR to produce multicarbon products via a tandem route. [ABSTRACT FROM AUTHOR]

The highly selective production of reduced multicarbon products with long‐term durability for CO2 electroreduction reaction (CO2RR) using clean and renewable electricity is currently a major challenge. Copper nanoparticles (Cu NPs) are exceptionally advantageous for CO2RR to yield multielectron transfer chemical products such as ethylene and ethanol. However, Cu NPs for CO2RR generally require high overpotential to produce multiple electron transfer C2+ products with poor stability. Herein, an imidazolium‐functionalized covalent triazine framework (ICTF) stabilized Cu NPs (Cu/ICTF) for the enhanced CO2RR to produce ethylene is reported. The imidazolium groups in the cationic ICTF not only can enhance CO2 capture capacity and lower the energetic barrier to activate CO2, but also the in situ formed N‐heterocyclic carbenes (NHC) could stabilize Cu NPs to prevent their deactivation. Thus, the Cu/ICTF demonstrated higher selectivity (35 %) for the electroreduction of CO2 to ethylene with larger partial current density of ethylene (4.14 mA cm−2) over the unmodified neutral CTF stabilized Cu NPs (Cu/CTF) with 29 % Faradaic efficiency (FE) of ethylene and current density of 3.69 mA cm−2. Moreover, the active sites could be stabilized by the in situ produced NHC in ICTF and the current density and C2H4 FE of Cu/ICTF50 were almost maintained after 10 h continuous electrolysis experiment, while the C2H4 FE of Cu/CTF50 were lost ca. 42 % of its original value after 7 h. This strategy provides a facile approach to stabilize active sites for CO2RR and may bring new inspiration to apply in energy storage and conversion. [ABSTRACT FROM AUTHOR]

Background: Noninvasive prognostic tools for esophageal squamous cell carcinoma (ESCC) are urgently needed. Serum lipids and lipoproteins are used for the prognosis of certain diseases; however, the prognostic value of serum apolipoprotein A-I (ApoA-I) in ESCC has not been described.Methods: Pre-treatment serum lipids and lipoprotein concentrations (including ApoA-I, Apo-B, HDL-C, LDL-C, TC and TG) were analyzed retrospectively and compared between 210 patients with ESCC and 219 healthy controls. The prognostic significance of serum lipids and lipoproteins was determined by univariate and multivariate Cox hazard models in ESCC.Results: Clinical characteristics (age, sex, pT status, pN status, pM status, pTNM status, histological differentiation or alcohol index) had no influence on baseline ApoA-I level. Serum ApoA-I, HDL-C, LDL-C, and TC levels were significantly lower and Apo-B was significantly higher in ESCC patients than in normal controls. On univariate analysis, ApoA-I, alcohol index, pT status, pN status and pTNM status were associated with significantly poor survival, and ApoA-I (p = 0.039), alcohol index (p = 0.037) and pTNM status (p = 0.000) were identified as prognostic factors associated with shorter survival in the multivariate analysis.Conclusions: Overall survival was shorter in ESCC patients with decreased pre-treatment ApoA-I levels. Our findings suggest that serum ApoA-I level should be evaluated as a predictor of survival in patients with ESCC. [ABSTRACT FROM AUTHOR]

Herein, an effective tandem catalysis strategy is developed to improve the selectivity of the CO 2 RR towards C 2 H 4 by multiple distinct catalytic sites in local vicinity. An earth-abundant elements-based tandem electrocatalyst PTF(Ni)/Cu is constructed by uniformly dispersing Cu nanoparticles (NPs) on the porphyrinic triazine framework anchored with atomically isolated nickel-nitrogen sites (PTF(Ni)) for the enhanced CO 2 RR to produce C 2 H 4 . The Faradaic efficiency of C 2 H 4 reaches 57.3 % at -1.1 V versus the reversible hydrogen electrode (RHE), which is about 6 times higher than the non-tandem catalyst PTF/Cu, which produces CH 4 as the major carbon product. The operando infrared spectroscopy and theoretic density functional theory (DFT) calculations reveal that the local high concentration of CO generated by PTF(Ni) sites can facilitate the C-C coupling to form C 2 H 4 on the nearby Cu NP sites. The work offers an effective avenue to design electrocatalysts for the highly selective CO 2 RR to produce multicarbon products via a tandem route., (© 2021 Wiley-VCH GmbH.)

Covalent organic frameworks (COFs) are promising candidates for electrocatalytic reduction of carbon dioxide into valuable chemicals due to their porous crystalline structures and tunable single active sites, but the low conductivity leads to unmet current densities for commercial application. The challenge is to create conductive COFs for highly efficient electrocatalysis of carbon dioxide reduction reaction (CO 2 RR). Herein, a porphyrin-based COF containing donor-acceptor (D-A) heterojunctions, termed TT-Por(Co)-COF, is constructed from thieno[3,2-b]thiophene-2,5-dicarbaldehyde (TT) and 5,10,15,20-tetrakis(4-aminophenyl)-porphinatocobalt (Co-TAPP) via imine condensation reaction. Compared with COF-366-Co without TT, TT-Por(Co)-COF displays enhanced CO 2 RR performance to produce CO due to its favorable charge transfer capability from the electron donor TT moieties to the acceptor Co-porphyrin ring active center. The combination of strong charge transfer properties and enormous amount of accessible active sites in the 2D TT-Por(Co)-COF nanosheets results in good catalytic performance with a high Faradaic efficiency of CO (91.4%, -0.6 V vs reversible hydrogen electrode (RHE) and larger partial current density of 7.28 mA cm -2 at -0.7 V versus RHE in aqueous solution. The results demonstrate that integration of D-A heterojunctions in COF can facilitate the intramolecular electron transfer, and generate high current densities for CO 2 RR., (© 2020 Wiley-VCH GmbH.)