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"Jia, Nan"
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Regulating Fe-spin state by atomically dispersed Mn-N in Fe-N-C catalysts with high oxygen reduction activity
As low-cost electrocatalysts for oxygen reduction reaction applied to fuel cells and metal-air batteries, atomic-dispersed transition metal-nitrogen-carbon materials are emerging, but the genuine mechanism thereof is still arguable. Herein, by rational design and synthesis of dual-metal atomically dispersed Fe,Mn/N-C catalyst as model object, we unravel that the O
2
reduction preferentially takes place on Fe
III
in the FeN
4
/C system with intermediate spin state which possesses one e
g
electron (t
2g
4e
g
1) readily penetrating the antibonding π-orbital of oxygen. Both magnetic measurements and theoretical calculation reveal that the adjacent atomically dispersed Mn-N moieties can effectively activate the Fe
III
sites by both spin-state transition and electronic modulation, rendering the excellent ORR performances of Fe,Mn/N-C in both alkaline and acidic media (halfwave positionals are 0.928 V in 0.1 M KOH, and 0.804 V in 0.1 M HClO
4
), and good durability, which outperforms and has almost the same activity of commercial Pt/C, respectively. In addition, it presents a superior power density of 160.8 mW cm
−2
and long-term durability in reversible zinc–air batteries. The work brings new insight into the oxygen reduction reaction process on the metal-nitrogen-carbon active sites, undoubtedly leading the exploration towards high effective low-cost non-precious catalysts.
The working mechanism of several low-cost electrocatalyst materials is still arguable. Here the authors show a model Fe,Mn/N-C catalyst where the oxygen reduction preferentially takes place on Fe(III) sites with the intermediate spin state (t2g4 eg1) caused by the adjacent Mn-N moieties.
Journal Article
Coordination environment dependent selectivity of single-site-Cu enriched crystalline porous catalysts in CO2 reduction to CH4
The electrochemical CO
2
reduction to high-value-added chemicals is one of the most promising and challenging research in the energy conversion field. An efficient ECR catalyst based on a Cu-based conductive metal-organic framework (Cu-DBC) is dedicated to producing CH
4
with superior activity and selectivity, showing a Faradaic efficiency of CH
4
as high as ~80% and a large current density of −203 mA cm
−2
at −0.9 V vs. RHE. The further investigation based on theoretical calculations and experimental results indicates the Cu-DBC with oxygen-coordinated Cu sites exhibits higher selectivity and activity over the other two crystalline ECR catalysts with nitrogen-coordinated Cu sites due to the lower energy barriers of Cu-O
4
sites during ECR process. This work unravels the strong dependence of ECR selectivity on the Cu site coordination environment in crystalline porous catalysts, and provides a platform for constructing highly selective ECR catalysts.
Crystalline porous catalysts with single Cu sites are dedicated to exploring the dependence of CO
2
electroreduction selectivity on the coordination environment of catalytic sites. The conductive MOF Cu-DBC with oxygen-coordinated Cu sites shows a high Faradaic efficiency ~80% of CO
2
-to-CH
4
.
Journal Article
Local mutational diversity drives intratumoral immune heterogeneity in non-small cell lung cancer
Combining whole exome sequencing, transcriptome profiling, and T cell repertoire analysis, we investigate the spatial features of surgically-removed biopsies from multiple loci in tumor masses of 15 patients with non-small cell lung cancer (NSCLC). This revealed that the immune microenvironment has high spatial heterogeneity such that intratumoral regional variation is as large as inter-personal variation. While the local total mutational burden (TMB) is associated with local T-cell clonal expansion, local anti-tumor cytotoxicity does not directly correlate with neoantigen abundance. Together, these findings caution against that immunological signatures can be predicted solely from TMB or microenvironmental analysis from a single locus biopsy.
Intratumoral immunity heterogeneity is poorly characterized. Here the authors apply exome sequencing, transcriptome profiling and T-cell repertoire profiling to multiple loci of non-small-cell lung cancer patients' biopsies and find high spatial immune heterogeneity with local mutational burden correlating with T-cell clonal expansion but not with cytotoxicity.
Journal Article
Dual-site segmentally synergistic catalysis mechanism: boosting CoFeSx nanocluster for sustainable water oxidation
Efficient oxygen evolution reaction electrocatalysts are essential for sustainable clean energy conversion. However, catalytic materials followed the conventional adsorbate evolution mechanism (AEM) with the inherent scaling relationship between key oxygen intermediates *OOH and *OH, or the lattice-oxygen-mediated mechanism (LOM) with the possible lattice oxygen migration and structural reconstruction, which are not favorable to the balance between high activity and stability. Herein, we propose an unconventional Co-Fe dual-site segmentally synergistic mechanism (DSSM) for single-domain ferromagnetic catalyst CoFeS
x
nanoclusters on carbon nanotubes (CNT) (CFS-ACs/CNT), which can effectively break the scaling relationship without sacrificing stability. Co
3+
(L.S,
t
2g
6
e
g
0
) supplies the strongest OH* adsorption energy, while Fe
3+
(M.S,
t
2g
4
e
g
1
) exposes strong O* adsorption. These dual-sites synergistically produce of Co-O-O-Fe intermediates, thereby accelerating the release of triplet-state oxygen ( ↑ O = O ↑ ). As predicted, the prepared CFS-ACs/CNT catalyst exhibits less overpotential than that of commercial IrO
2
, as well as approximately 633 h of stability without significant potential loss.
Efficient oxygen evolution reaction electrocatalysts are essential for sustainable clean energy conversion. Here, the authors propose a Co-Fe dual-site to facilitate the ferromagnetic O-O bond coupling to achieve a great balance between activity and stability.
Journal Article
Spin occupancy regulation of the Pt d-orbital for a robust low-Pt catalyst towards oxygen reduction
Disentangling the limitations of O-O bond activation and OH* site-blocking effects on Pt sites is key to improving the intrinsic activity and stability of low-Pt catalysts for the oxygen reduction reaction (ORR). Herein, we integrate of PtFe alloy nanocrystals on a single-atom Fe-N-C substrate (PtFe@Fe
SAs
-N-C) and further construct a ferromagnetic platform to investigate the regulation behavior of the spin occupancy state of the Pt
d
-orbital in the ORR. PtFe@Fe
SAs
-N-C delivers a mass activity of 0.75 A mg
Pt
−1
at 0.9 V and a peak power density of 1240 mW cm
−2
in the fuel-cell, outperforming the commercial Pt/C catalyst, and a mass activity retention of 97%, with no noticeable current drop at 0.6 V for more than 220 h, is attained.
Operando
spectroelectrochemistry decodes the orbital interaction mechanism between the active center and reaction intermediates. The Pt
dz
2
orbital occupation state is regulated to
t
2g
6
e
g
3
by spin-charge injection, suppressing the OH* site-blocking effect and effectively inhibiting H
2
O
2
production. This work provides valuable insights into designing high-performance and low-Pt catalysts via spintronics-level engineering.
Developing highly durable and active low-platinum electrocatalysts is crucial for advancing proton exchange membrane fuel cell technology. Here, the authors report PtFe on a single-atom Fe-N-C substrate to regulate the spin occupancy state of the Pt d-orbital for enhanced oxygen reduction reaction in proton exchange membrane fuel cell.
Journal Article
Important role of Fe oxides in global soil carbon stabilization and stocks
Iron (Fe) oxides can interact with soil organic carbon (SOC) to form Fe-bound organic carbon (OC-Fe), which strongly promotes SOC protection, mitigating global climate change. However, the global patterns and factors controlling OC-Fe are unclear. Here, we conducted a meta-analysis of 3,395 globally distributed soil profiles to reveal the role of Fe-Al oxides in global soil carbon stabilization and stocks. The global OC-Fe stock in topsoil is 233 PgC, accounting for 33 ± 15% of the total SOC stock. A substantial OC-Fe deficit (difference between OC-Fe and OC-Fe
max
) was observed at the equator and at mid-latitudes. Our findings suggest that mineral factors should be incorporated into soil carbon models to improve model predictions. Although there are uncertainties in current OC-Fe extraction method, the global distribution of OC-Fe and OC-Fe
max
constitutes a vital resource for future research targeting carbon cycling issues and offers innovative strategies for global soil carbon sequestration initiatives.
Iron oxides stabilize soil organic carbon globally, with OC-Fe accounting for 33 ± 15% of SOC in topsoil (233 PgC). A global OC-Fe deficit is evident at the equator and mid-latitudes, highlighting opportunities for carbon sequestration strategies
Journal Article
The Dynamics of Political Embeddedness in China
Economic transitions in countries that move from state planning and redistribution to market exchange create business opportunities but also uncertainty, because many interdependent factors—modes of exchange, types of products, and forms of organizations—are in flux. Uncertainty is even greater when the country's political institutions remain authoritarian because the rule of law is weak and state bureaucrats retain power over the economy. This study of listed firms in China, which has recently seen economic transition but persistent authoritarianism, shows that in such contexts, firms can reduce uncertainty by developing relationships with state bureaucrats, which help firms learn how state bureaucracies operate and engender trust between firms and bureaucrats. Together, knowledge and trust stabilize operations and help persuade bureaucrats to lighten regulatory burdens, grant firms access to state-controlled resources, and improve government oversight. Our results show that as economic transitions proceed and uncertainty increases, business-state ties increasingly improve firm performance. We also investigate two likely contingencies, industry and firm size, and two important causal mechanisms, access to bank loans and protection from related-party loans, and show that the value of business-state relations varies over time, depending on the trajectory of both economic and political institutions.
Journal Article
Application and optimization of adaptive genetic algorithm in fencing training load prediction: a data visualization-based analytical approach
This study proposes an Adaptive Genetic Algorithm (AGA) model for predicting training load in fencing. Training load is defined using external mechanical load collected from sensors and is categorized into six components: strength, aerobic, capacity, endurance, speed, agility, and flexibility. The study employs the publicly available Daily and Sports Activities dataset, which includes data from eight healthy adults (four females and four males, aged 20–30) performing 19 types of activities. Time-series segments are mapped to fencing-related load patterns for model training and evaluation. The proposed AGA dynamically adjusts the fitness function, crossover rate, and mutation rate. Its performance is compared with several models, including Deep Neural Network with Gated Recurrent Unit (DNN-GRU), Extreme Gradient Boosting (XGBoost), Long Short-Term Memory with Attention Mechanism (LSTM-Attn), Event Adversarial Neural Network (EANN), and Temporal Attention Graph Convolutional Network (TA-GCN). The results show that the AGA consistently outperformed all comparison methods in terms of prediction error and goodness-of-fit. For example, in endurance load prediction, the test set achieves an R
2
of 0.97 and an accuracy of 0.96. Time-series visualizations are used to analyze typical and extreme load segment, where extreme load is defined as time windows in which the predicted external load falls within the top decile. Overall, the findings demonstrate that the optimized AGA framework provides reliable training load predictions while maintaining computational efficiency. This approach offers a practical reference for data-driven training monitoring and training planning in fencing and related sports.
Journal Article
Immune Landscape of Colorectal Cancer Tumor Microenvironment from Different Primary Tumor Location
To define differences in tumor microenvironment (TME) immune phenotypes between right and left colorectal cancers (CRCs) and explore their therapeutic implications. Gene expression profiling and clinical characteristics of patients with CRC were retrieved from The Cancer Genome Atlas data portal. Immune cell infiltration was estimated based on single-sample gene set enrichment analysis. CRCs tissue microarrays (TMAs) containing 90 consecutive cases of surgical samples were used for validation. Expression of CD8A and VEGFA was confirmed by immunohistochemistry (IHC) analysis with TMAs, and overall survival (OS) was analyzed. Expression profiling data demonstrated that CRC immune microenvironment from right side tumor was characterized as increased infiltration of immune cells with enhanced cytotoxic function, based on higher cytotoxic activity scores (CYT) and interferon-γ signatures. Expression of VEGFA, which could be neutralized by bevacizumab, was associated with decreased levels of activated CD8
T-cells, Th1 cells, and PRF1 expression on the right side, but not on the left side. IHC analysis of TMAs further confirmed an inverse correlation between CD8A and VEGFA expression, and revealed a favorable OS for patients with CD8A
VEGFA
disease among right-side CRCs. For the left side, higher CD56
natural killer cell infiltration and active 4-1BB/IFN-ɑ signaling, which could providing a favorable condition for cetuximab-mediated antibody-dependent cell-mediated cytotoxicity effect, was present in a cohort with extended OS. In the TME, features of immune phenotype sidedness were identified, providing an implication for differential responses to bevacizumab/cetuximab treatment. In addition, a new avenue for innovative experimental design and combinational immunotherapy to treat CRC patients was suggested.
Journal Article