As am etal-free nitrogen reduction reaction (NRR) photocatalyst, g-C 3 N 4 is available from as calable synthesis at low cost. Importantly,i tc an be readily functionalizedt o enhance photocatalytic activities.H owever,t he use of g-C 3 N 4based photocatalysts for the NRR has been questioned because of the elusive mechanism and the involvement of Nd efects. This work reports the synthesis of ag -C 3 N 4 photocatalyst modified with cyano groups and intercalated K + (mCNN), possessing extended visible-light harvesting capacity and superior photocatalytic NRR activity (NH 3 yield: 3.42 mmol g À1 h À1 ). Experimental and theoretical studies suggest that the -C Ni nm CNN can be regenerated through ap athway analogous to Mars van Krevelen process with the aid of the intercalated K + .T he results confirm that the regeneration of the cyano group not only enhances photocatalytic activity and sustains the catalytic cycle,b ut also stabilizes the photocatalyst.
Single‐atom catalysts have demonstrated their superiority over other types of catalysts for various reactions. However, the reported nitrogen reduction reaction single‐atom electrocatalysts for the nitrogen reduction reaction exclusively utilize metal–nitrogen or metal–carbon coordination configurations as catalytic active sites. Here, we report a Fe single‐atom electrocatalyst supported on low‐cost, nitrogen‐free lignocellulose‐derived carbon. The extended X‐ray absorption fine structure spectra confirm that Fe atoms are anchored to the support via the Fe‐(O‐C2)4 coordination configuration. Density functional theory calculations identify Fe‐(O‐C2)4 as the active site for the nitrogen reduction reaction. An electrode consisting of the electrocatalyst loaded on carbon cloth can afford a NH3 yield rate and faradaic efficiency of 32.1 μg h−1 mgcat.−1 (5350 μg h−1 mgFe−1) and 29.3 %, respectively. An exceptional NH3 yield rate of 307.7 μg h−1 mgcat.−1 (51 283 μg h−1 mgFe−1) with a near record faradaic efficiency of 51.0 % can be achieved with the electrocatalyst immobilized on a glassy carbon electrode.
The Haber‐Bosch process can be replaced by the ambient electrocatalytic N2 reduction reaction (NRR) to produce NH3 if suitable electrocatalysts can be developed. However, to develop high performance N2 fixation electrocatalysts, a key issue to be resolved is to achieve efficient hydrogenation of N2 without interference by the thermodynamically favored hydrogen evolution reaction (HER). Herein, in‐operando created strong Li–S interactions are reported to empower the S‐rich MoS2 nanosheets with superior NRR catalytic activity and HER suppression ability. The Li+ interactions with S‐edge sites of MoS2 can effectively suppress hydrogen evolution reaction by reducing H* adsorption free energy from 0.03 to 0.47 eV, facilitate N2 adsorption by increasing N2 adsorption free energy from –0.32 to –0.70 eV and enhance electrocatalytic N2 reduction activity by decreasing the activation energy barrier of the reaction control step (*N2 → *N2H) from 0.84 to 0.42 eV. A NH3 yield rate of 43.4 μg h−1 mg−1 MoS2 with a faradaic efficiency (FE) of 9.81% can be achieved in presence of strong Li–S interactions, more than 8 and 18 times by the same electrocatalyst in the absence of Li–S interactions. This report opens a new way to design and develop catalysts and catalysis systems.
The electrochemical reduction of
CO2 to produce carbon-based
fuels and chemicals possesses huge potentials to alleviate current
environmental problems. However, it is confronted by great challenges
in the design of active electrocatalysts with low overpotentials and
high product selectivity. Here we report the atomic tuning of a single-Fe-atom
catalyst with phosphorus (Fe–N/P–C) on commercial carbon
black as a robust electrocatalyst for CO2 reduction. The
Fe–N/P–C catalyst exhibits impressive performance in
the electrochemical reduction of CO2 to CO, with a high
Faradaic efficiency of 98% and a high mass-normalized turnover frequency
of 508.8 h–1 at a low overpotential of 0.34 V. On
the basis of ex-situ X-ray absorption spectroscopy
measurements and DFT calculations, we reveal that the tuning of P
in single-Fe-atom catalysts reduces the oxidation state of the Fe
center and decreases the free-energy barrier of *CO intermediate formation,
consequently maintaining the electrocatalytic activity and stability
of single-Fe-atom catalysts.
Cu doping in CeO2 nanorods can effectively induce formation of multiple oxygen vacancies around the Cu doping sites, dramatically facilitating the N2 reduction performance under ambient conditions.
Here we report that alfalfa-derived nitrogen-doped porous carbon
(NPC) fabricated by a pyrolysis method is electrochemically active
for the N2 reduction reaction (NRR) at ambient conditions.
The results demonstrate that the obtained NPC material with a nitrogen
content of 6.35 atom % at 500 °C (NPC-500) exhibits high NRR
activity with an NH3 yield rate of 1.31 mmol h–1 g–1
cat. and a Faradaic efficiency of
9.98% at −0.4 V (vs RHE) in 0.005 M H2SO4 solution. The isotopic labeling experimental results using 15N2 feed gas and 15NPC-500 reveal that
the yielded NH3 indeed resulted from the NPC-500 catalyzed
NRR, and the doped pyridinic-N also contributes NH3 formation
during NRR. The experimental and theoretical calculations results
indicate that the doped pyridinic-N in the NPC catalyst during NRR
can break away from its surface to form N vacancies in a carbon matrix
as the catalytic active sites for N2 adsorption and activation.
Community-acquired pneumonia (CAP) contributes substantially to morbidity and mortality in children under the age of 5 years. In examining bronchoalveolar lavages (BALs) of children with CAP, we found that interleukin-17 (IL-17) production was significantly increased in severe CAP. Immune profiling showed that mucosal-associated invariant T (MAIT) cells from the BALs, but not blood, of CAP patients actively produced IL-17 (MAIT17). Single-cell RNA-sequencing revealed that MAIT17 resided in a BAL-resident PLZF hi CD103 + MAIT subset with high expression of hypoxia-inducible factor 1α (HIF-1α), reflecting the hypoxic state of the inflamed tissue. CAP BALs also contained a T-bet + MAIT1 subset and a novel DDIT3 + (DNA damage-inducible transcript 3-positive) MAIT subset with low expression of HIF1A. Furthermore, MAIT17 differed from T-helper type 17 (Th17) cells in the expression of genes related to tissue location, innateness, and cytotoxicity. Finally, we showed that BAL monocytes were hyper-inflammatory and elicited differentiation of MAIT17. Thus, tissue-resident MAIT17 cells are induced at the infected respiratory mucosa, likely influenced by inflammatory monocytes, and contribute to IL-17-mediated inflammation during CAP.Mucosal Immunology _#####################_ ; https://doi.
Building occupants are continuously exposed to multiple indoor environmental stimuli, including thermal, visual, acoustic, and air quality related factors. Moreover, personal and contextual aspects can be regarded as additional domains influencing occupants' perception and behaviour. The scientific literature in this area typically deals with these multiple stimuli in isolation. In contrast to single-domain research, multi-domain research analyses at least two different domains, for example, visual and thermal. The relatively few literature reviews that have considered multi-domain approaches to indoor-environmental perception and behaviour covered only a few dozen articles each. The present contribution addresses this paucity by reviewing 219 scientific papers on interactions and cross-domain effects that influence occupants' indoor environmental perception and behaviour. The objective of the present review is to highlight motivational backgrounds, key methodologies, and major findings of multi-domain investigations of human perception and behaviour in indoor environments. The in-depth review of these papers provides not only an overview of the state of the art, but also contributes to the identification of existing knowledge gaps in this area and the corresponding need for future research. In particular, many studies use "convenience" variables and samples, there is often a lack of theoretical foundation to studies, and there is little research linking perception to action.
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