A novel in situ replication and polymerization strategy is developed for the synthesis of Fe‐N‐doped mesoporous carbon microspheres (Fe‐NMCSs). This material benefits from the synergy between the ...high catalytic activity of Fe‐N‐C and the fast mass transport of the mesoporous microsphere structure. Compared to commercial Pt/C catalysts, the Fe‐NMCSs show a much better electrocatalytic performance in terms of higher catalytic activity, selectivity, and durability for the oxygen reduction reaction.
Ammonia synthesis is one of the most kinetically complex and energetically challenging chemical processes in industry and has used the Harber–Bosch catalyst for over a century, which is processed ...under both harsh pressure (150–350 atm) and hightemperature (623–823 K), wherein the energy and capital intensive Harber–Bosch process has a huge energy cost accounting for about 1%–3% of human's energy consumption. Therefore, there has been a rough and vigorous exploration to find an environmentally benign alternative process. As the amorphous material is in a metastable state and has many “dangling bonds”, it is more active than the crystallized one. In this paper, CeOx‐induced amorphization of Au nanoparticles anchored on reduced graphite oxide (a‐Au/CeOx–RGO) has been achieved by a facile coreduction method under ambient atmosphere. As a proof‐of‐concept experiment, a‐Au/CeOx–RGO hybrid catalyst containing the low noble metal (Au loading is 1.31 wt%) achieves a high Faradaic efficiency (10.10%) and ammonia yield (8.3 μg h−1 mg−1cat.) at −0.2 V versus RHE, which is significantly higher than that of the crystalline counterpart (c‐Au/RGO), and even comparable to the yields and efficiencies under harsh temperatures and/or pressures.
CeOx‐induced amorphization of Au nanoparticles anchored on reduced graphite oxide (a‐Au/CeOx–RGO) as a heterogeneous electrocatalyst shows excellent catalytic activity for electrochemical N2 reduction reaction with high Faradic efficiency (10.10%) and ammonia yield (8.3 μg h‐1 mg‐1cat.)
As an alternative approach for N2 fixation under milder conditions, electrocatalytic nitrogen reduction reaction (NRR) represents a very attractive strategy for sustainable development and N2 cycle ...to store and utilize energy from renewable sources. However, the research on NRR electrocatalysts still mainly focuses on noble metals, while, high costs and limited resources greatly restrict their large‐scale applications. Herein, as a proof‐of‐concept experiment, taking PdCu amorphous nanocluster anchored on reduced graphene oxide (rGO) as NRR catalysts, the optimum Pd0.2Cu0.8/rGO composite presents a synergistic effect and shows superior electrocatalytic performance toward NRR under ambient conditions (yield: 2.80 µg h−1 mgcat.−1 at −0.2 V vs reversible hydrogen electrode), which is much higher than that of monometallic, especially noble metal, counterparts. The superior catalytic performance of alloy catalysts with low noble metal loading would strongly spur interest toward more researches on NRR catalysts in the future.
PdCu amorphous nanoclusters anchored on graphene are successfully synthesized by a facile coreduction route. The optimum Pd0.2Cu0.8/rGO sample presents enhanced electrocatalytic performance toward electrochemical N2 fixation to NH3 under ambient conditions.
As the NN bond in N2 is one of the strongest bonds in chemistry, the fixation of N2 to ammonia is a kinetically complex and energetically challenging reaction and, up to now, its synthesis is still ...heavily relying on energy and capital intensive Haber–Bosch process (150–350 atm, 350–550 °C), wherein the input of H2 and energy are largely derived from fossil fuels and thus result in large amount of CO2 emission. In this paper, it is demonstrated that by using Au sub‐nanoclusters (≈0.5 nm ) embedded on TiO2 (Au loading is 1.542 wt%), the electrocatalytic N2 reduction reaction (NRR) is indeed possible at ambient condition. Unexpectedly, NRR with very high and stable production yield (NH3: 21.4 µg h−1 mg−1cat., Faradaic efficiency: 8.11%) and good selectivity is achieved at −0.2 V versus RHE, which is much higher than that of the best results for N2 fixation under ambient conditions, and even comparable to the yield and activation energy under high temperatures and/or pressures. As isolated precious metal active centers dispersed onto oxide supports provide a well‐defined system, the special structure of atomic Au cluster would promote other important reactions besides NRR for water splitting, fuel cells, and other electrochemical devices.
Using Au sub‐nanoclusters anchored on TiO2 substrate as a heterogeneous electrocatalyst, the special Au active sites lead to the effective and stable electrochemical N2 reduction reaction with high NH3 yield (21.4 µg h−1 mg−1cat.) and Faradaic efficiency (8.11%) as well as 100% NH3 selectivity at ambient conditions.
Formic acid (HCOOH) is one of the most promising chemical fuels that can be produced through CO2 electroreduction. However, most of the catalysts for CO2 electroreduction to HCOOH in aqueous solution ...often suffer from low current density and limited production rate. Herein, we provide a bismuth/cerium oxide (Bi/CeOx) catalyst, which exhibits not only high current density (149 mA cm−2), but also unprecedented production rate (2600 μmol h−1 cm−2) with high Faradaic efficiency (FE, 92 %) for HCOOH generation in aqueous media. Furthermore, Bi/CeOx also shows favorable stability over 34 h. We hope this work could offer an attractive and promising strategy to develop efficient catalysts for CO2 electroreduction with superior activity and desirable stability.
The limited current density, production rate as well as selectivity hinder the improvement of HCOOH production from CO2 electroreduction. Here, bismuth/cerium oxide (Bi/CeOx) displays outstanding performances for CO2 electroreduction to HCOOH, which not only shows excellent selectivity, but also achieves a high current density (149 mA cm−2) and especially the maximum HCOOH production rate (2600 μmol h−1 cm−2) ever reported.
Colorectal cancer (CRC) is one of the most common cancers in the world. Oxidative stress reactions have been reportedly associated with oncogenesis and tumor progression. By analyzing mRNA expression ...data and clinical information from The Cancer Genome Atlas (TCGA), we aimed to construct an oxidative stress-related long noncoding RNA (lncRNA) risk model and identify oxidative stress-related biomarkers to improve the prognosis and treatment of CRC.
Differentially expressed oxidative stress-related genes (DEOSGs) and oxidative stress-related lncRNAs were identified by using bioinformatics tools. An oxidative stress-related lncRNA risk model was constructed based on 9 lncRNAs (AC034213.1, AC008124.1, LINC01836, USP30-AS1, AP003555.1, AC083906.3, AC008494.3, AC009549.1, and AP006621.3) by least absolute shrinkage and selection operator (LASSO) analysis. The patients were then divided into high- and low-risk groups based on the median risk score. The high-risk group had a significantly worse overall survival (OS) (p < 0.001). Receiver operating characteristic (ROC) and calibration curves displayed the favorable predictive performance of the risk model. The nomogram successfully quantified the contribution of each metric to survival, and the concordance index and calibration plots demonstrated its excellent predictive capacity. Notably, different risk subgroups showed significant differences in terms of their metabolic activity, mutation landscape, immune microenvironment and drug sensitivity. Specifically, differences in the immune microenvironment implied that CRC patients in certain subgroups might be more responsive to immune checkpoint inhibitors.
Oxidative stress-related lncRNAs can predict the prognosis of CRC patients, which provides new insight for future immunotherapies based on potential oxidative stress targets.
In this paper, we are concerned with the boundary feedback stabilization of a cascade of heat PDE–ODE system with Dirichlet/Neumann interconnection and with the external disturbance flowing the ...control end. In order to deal with the disturbance, the sliding model control (SMC) is integrated with the backstepping approach, where the disturbance is supposed to be bounded only. The existence and uniqueness of the solution for the closed-loop system are proved, and the monotonicity of the “reaching condition” is presented without differentiation of the sliding mode function, for which it may not always exist for the weak solution of the closed-loop system. Finally the numerical simulations validate the effectiveness of this method for the system with periodic and normal random disturbances respectively.
Converting N2 to NH3 is an extremely valuable process but a long‐standing challenge in chemistry. The crux is the choice of catalysts, where single atomic catalysts (SAC) are always pursued as the ...altar of atomic catalysts. In this paper, double atomic catalysts (DAC) of TM2‐C2N with SAC of TM‐C2N (TM = Cr, Mn, Fe, Co, and Ni) for nitrogen reduction reaction (NRR) are systematically compared. Unexpectedly, TM2‐C2N are more suitable than TM‐C2N as catalysts for NRR. Moreover, the Mn2‐C2N endows the highest catalytic activity with the lowest potential of −0.23 V versus RHE, which is the best among all reported calculation results for NRR under ambient conditions. As a result, a new way to design catalysts with DAC is provided.
Double atomic catalysts will become the altar of atomic catalysts for nitrogen reduction reaction instead of single atomic catalysts. Moreover, the Mn2‐C2N has the highest catalytic activity with the potential of −0.23 V versus reversible hydrogen electrode, indicating the promising catalyst for practical applications.
Ammonia, as an important chemical, has played an indispensable role in the fields of fertilizer precursors, fuel, and energy carriers over time. The electrocatalytic nitrogen reduction reaction ...(eNRR) has attracted extensive attention due to the potential availability of clean energy under mild conditions, while electrochemical catalysts still need further optimization and exploration restricted by the strong chemical bonds of NN. In this work, it is proposed that a small amount of noble metal (Au) modified Fe2(MoO4)3 can serve as active sites in eNRR. Density functional theory calculations reveal that the interaction of Au with Fe2(MoO4)3 reduces the reaction energy of the rate determining step and inhibits the hydrogen evolution reaction, which increase the eNRR activity and selectivity of Au/Fe2(MoO4)3. As expected, according to the 1H nuclear magnetic resonance measurement as the exclusive quantitative detection approach, the as‐prepared Au/Fe2(MoO4)3 achieves outstanding eNRR performance with 7.61 µg h−1 mg−1cat. NH3 production rate and 18.79% Faradaic efficiency at −0.4 V versus reversible hydrogen electrode in 0.2 m Na2SO4 under ambient conditions.
Au nanoparticles modified Fe2(MoO4)3 shows a high Faradaic efficiency of 18.79% and NH3 yield rate of 7.61 µg h−1 mg−1cat. Based on the theoretical calculations, the Mo atoms adjacent to Au serve as catalytic centers for reducing the reaction energy of the rate determining step and inhibiting the hydrogen evolution reaction, which accounts for the brilliant nitrogen electroreduction performance of Au/Fe2(MoO4)3.
Conversion of carbon dioxide (CO2) into valuable chemicals, especially liquid fuels, through electrochemical reduction driven by sustainable energy sources, is a promising way to get rid of ...dependence on fossil fuels, wherein developing of highly efficient catalyst is still of paramount importance. In this study, as a proof‐of‐concept experiment, first a facile while very effective protocol is proposed to synthesize amorphous Cu NPs. Unexpectedly, superior electrochemical performances, including high catalytic activity and selectivity of CO2 reduction to liquid fuels are achieved, that is, a total Faradaic efficiency of liquid fuels can sum up to the maximum value of 59% at −1.4 V, with formic acid (HCOOH) and ethanol (C2H6O) account for 37% and 22%, respectively, as well as a desirable long‐term stability even up to 12 h. More importantly, this work opens a new avenue for improved electroreduction of CO2 based on amorphous metal catalysts.
An amorphous Cu catalyst displays superior catalytic activity toward electroreduction of CO2 with a remarkable selectivity for the reduction to liquid fuels (HCOOH andC2H6O) relative to a crystalline Cu catalyst.
