As functional materials in sorption-enhanced steam gasification of biomass (SEBSG) systems, Ni-CaO bifunctional materials (BFMs) suffer from sintering, coking, and kinetic limitations during cycling, which causes a gradual decline in hydrogen yield and purity. Herein, a novel Ca@(Ni@mp-Ce) architecture is proposed, featuring a mesoporous (mp) CeO2 shell that provides dual confinement, namely core-shell encapsulation for CaO and porechannel trapping for Ni particles. The mp-CeO2 shell enabled CaO to achieve faster rate constants in both the chemical-reaction and diffusion-controlled stages while effectively suppressing agglomeration. As a result, its CO2 capture capacity reached 0.52 g/g, with 94% retention after 10 cycles. The narrow Ni particle size distribution underpinned by mp-CeO2 restricted Ni grains growth to merely 1.4 times in 10th test. Ca@(Ni@mp-Ce) exhibited significantly reduced coke formation and two anti-coking pathways are proposed based on the synergy among oxygen supply from mp-CeO2, highly dispersed Ni and reactive CaO. Owing to enhanced sintering and coking resistance, Ca@(Ni@mp-Ce) achieved 85.9% H2 purity and 51.8 mmol/gbiomass H2 yield with 89% retention over 10 SEBSG cycles.

CO2 methanation technology enables the conversion of CO2 and green hydrogen into methane, thereby reducing CO2 emissions while simultaneously resolving the issues associated with the storage, transportation, and largescale utilization of green hydrogen. This reaction is exothermic and offers thermodynamic advantages at low temperatures. However, low temperatures also lead to kinetic limitations, which restrict the conversion rate. Therefore, enhancing the low-temperature catalytic activity of the catalyst is crucial. In this paper, CO2 methanation catalysts were prepared by co-loading Ce, Co, La and Y metal or metal oxide promoters with Ni on N-doping carbon nanotubes, and experimental research was carried out on a fixed bed. The addition of Ce significantly improved the low-temperature CO2 methanation performance of the catalyst. The 25Ni-5Ce/NCNTs catalyst achieves a CO2 conversion exceeding 90% and 100% selectivity toward methane at 280 degrees C with a gas hourly space velocity of 60,000 mL & sdot;g- 1 & sdot;h- 1. Remarkably, even upon lowering the reaction temperature to 220 degrees C, the catalyst maintains a high CO2 conversion of 84.9% while retaining full methane selectivity. After 100 h of continuous operation, the CO2 conversion of the 25Ni-5Ce/N-CNTs catalyst remains above 95% of its initial value, and the CH4 selectivity consistently remains at 100%. The results of CO2-TPD and H2-TPR show that the addition of Ce increases the number of adsorption sites on the catalyst surface, promotes the dispersion of Ni particles, and can alter the interaction between the active metal and the support. The test results of in situ DRIFTs indicate that the addition of Ce shifts the main reaction path of CO2 methanation from the CO pathway to the formate pathway. DFT calculations reveal that the cross-interface formed between CeO2 and Ni facilitates the adsorption and activation of CO2.

To address the issues of poor combustion stability and high NOx emissions in ammonia‑fueled catalytic combustion, this study proposes highly efficient LaMnO3 perovskite catalysts through A‑site and B‑site doping modification, aiming to enhance the catalytic activity and N2 selectivity. First, a WOA‑BP neural network model is established to predict the effects of different doping elements (A‑site: Sr, Ce, K, Ca; B‑site: Fe, Co, Cu, Al) on the catalytic performance, and is then synergistically integrated with the NSGA‑II multi‑objective genetic algorithm to efficiently explore the doping parameter space for co‑optimizing catalytic activity and N2 selectivity. The test results demonstrate that the optimal catalyst, La0.87Ce0.13Mn0.96Fe0.04O3, exhibits a T90 and N2 selectivity of 253.8°C and 48.9% respectively, representing a significant improvement over the unmodified catalyst. Further, characterization analyses reveal that Ce/Fe co‑doping effectively enhances the ammonia adsorption capacity of the catalyst due to the increased Mn4+ content and the concentration of surface‑adsorbed oxygen. In general, the study sheds light on a feasible design scheme of high‑performance catalysts, which contributes the high-efficiency and low-emission for renewable ammonia catalytic combustion.

An Fe–Mn DAC with the largest electronegativity difference among Fe-based pairs enabled sequential PMS activation and BPA oxidation, thereby overcoming the inherent scaling relationship limitation in PMS-based Fenton-like reaction.

Carbon dioxide electrochemical reduction (CO2RR) has great prospects in alleviating environmental problems caused by carbon dioxide emissions and achieving value-added products. Among these chemicals, formic acid is suggested to be one of the economically viable products for hydrogen storage material and chemical intermediates. The industrial production of formic acid is an energy-intensive process, so the production of formic acid in CO2RR under mild conditions has received extensive attention. The production of formic acid in the CO2RR depends on the development of highly active and selective electrocatalysts. In order to solve the electrocatalysts with low reaction activity, low formic acid formation rate and poor long-term stability in the CO2RR process, hollow nano-carbon sphere-supported bismuth oxide catalysts (Bi2O3@HCS) were prepared by template method. Metallic bismuth (Bi) has preferable HOCO* adsorption energy and hollow nanospheres have a good active component limiting effect. The chemical composition and surface morphology of the Bi2O3@HCS catalysts were in detail analyzed by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray powder diffractometer (XRD), and X-ray photoelectron spectroscopy (XPS). These results showed that the active components Bi0 and Bi2O3 were uniformly dispersed in the hollow carbon nanospheres, and in the Bi2O3@HCS-2 catalyst the highest Bi3+/Bi0 atomic ratio was achived. The sizes of Bi0 and Bi2O3 particles did not change significantly with increasing Bi loading from 2.0 to 3.0 mmol/L. The result was attributed to the confinement effect of hollow carbon nanospheres in the Bi2O3@HCS catalysts. The electrochemical capability of Bi2O3@HCS catalysts toward electrochemical CO2 reduction was investigated by Linear sweep voltammograms (LSV) test in phosphate solution (pH=6.8) saturated with CO2 or Ar. For Bi2O3@HCS-2 catalyst, the current density of CO2 reduction peak is the largest, which indicated that the higher activity of the Bi2O3@HCS-2 catalyst was obtained compared with both Bi2O3@HCS-1 and Bi2O3@HCS-3 in the CO2RR. Electrochemical impedance spectroscopy (EIS) was performed to investigate the electron transfer capability of the Bi2O3@HCS catalysts. The Bi2O3@HCS-2 catalyst exhibited a lower charge-transfer resistance, suggesting a more favorable electron transfer during CO2RR. The performance of Bi2O3@HCS catalysts in CO2RR for producing formic acid was investigated in a H-shaped electrolyzer. The Bi2O3@HCS-2 catalyst, with a Bi loading of 2.0 mmol/L, had the highest formic acid formation rate compared to Bi2O3@HCS-1 and Bi2O3@HCS-3 catalysts (the Bi loading was 1.0 mmol/L and 3.0 mmol/L, respectively). The effects of the reaction operating conditions (cathode potential, KHCO3 electrolyte concentration and pH) on the formation of formic acid were optimized in the CO2RR over the Bi2O3@HCS-2 catalyst. The results showed that the Bi2O3@HCS-2 catalyst with uniformly-sized particles showed the highest formic acid formation rate (1 108.11 μmol/L/h/cm2), and its Faradaic efficiency (FE) reached 54.73% in the H-type reactor under the condition of cathode potential of ‒1.1 V vs. RHE and electrolyte concentration of 0.1 mol/L KHCO3. In order to have an insight into the effects of formic acid formation rate under different pH conditions in the CO2RR over the Bi2O3@HCS-2 catalyst, phosphoric acid buffer solution was used as the electrolyte instead of KHCO3. The results showed that the Bi2O3@HCS-2 catalyst exhibited good adaptability in the CO2RR in a wide pH range. In addition, the good stability of the Bi2O3@HCS-2 catalyst in CO2RR for synthesis of formic acid was proved through the five successive cycle experiments. Compared with the formic acid formation rate in the literatures, the Bi2O3@HCS-2 catalyst showed good performance for the following reasons: 1) the hollow nanocarbon spheres with nanoconfinement effect inhibited the agglomeration of the active components of Bi0 and Bi2O3 nanoparticles; 2) the abundant Bi2O3 particles improved the reaction kinetics for the formic acid formation in the CO2RR; 3) the transition of the chemical valence state between Bi0 and Bi2O3 further accelerated the electron transfer capacity. This study on the electrochemical CO2 reduction for producing formic acid over the Bi2O3@HCS-2 catalysts provides a contribution for the synthesis of high-efficiency Bi-based nanocatalysts.

Transition metal single atom catalysts (SACs) for boosting peroxymonosulfate (PMS) activation involving complex catalytic mechanism and multiple reaction pathways have received much attention, but regulating the reaction pathway of SACs is still an important challenge in the PMS-mediated Fenton-like reaction. Herein, a boron-doped Fe SAC with FeN3B configurations (Fe-BNC) was synthesized and selectively generated a nonradical pathway, in which the high-valent iron-oxo species (FeIV--O) were determined as the main reactive oxygen species (ROS) by PMS activation. The Fe-BNC/PMS system not only exhibited remarkable reaction kinetic constant (0.949 min-1) and turnover frequency (9.49 L min-1g-1) for the phenol degradation, but also showed excellent selectivity to phenols with strong electron-donating ability. Mechanism exploration based on theoretical calculations revealed that high activity of Fe-BNC originated from the reinforced adsorption energy and enhanced overlap between Fe 3d and O 2p orbits, which facilitated to strengthen the Fe-O bonding and accelerate the electron transfer, thus modulating the PMS activation via a non-radical pathway. Successful extendibility of Fe-BNC in treatment of the real water and coking wastewater demonstrates its application potential. This work elucidates the mechanism of selectively generating a non-radical pathway over B-doped Fe-based SAC, and provides a rational strategy for preparing SACs alone with a non-radical pathway.

Fe–N 5 SAC efficiently activates peroxymonosulfate, resulting in remarkable 4-CP degradation efficiency with turnover frequency of 59.8 L (min g) −1 , and holds potential application in environmental remediation.

Catalytic ozonation could effectively purify the secondary effluent from IPWWTPs. ● High removal on COD, UV254 and TOC were obtained in the Mn-based catalyst/O3 system. ● Mn-based catalytic ozonation preferred to degrade aromatic contaminants in wastewater. ● ·O2‒/HO2· and 1O2 dominated contaminants removal in the Mn-based catalyst/O3 system. Catalytic ozonation is a potential technology to eliminate refractory organic contaminants with the low concentration in secondary effluent from industrial park wastewater treatment plants (IPWWTPs). In this study, the catalytic ozonation over the Mn-based catalyst significantly improved the chemical oxygen demand (COD), total organic carbon (TOC), and UV254 removals of secondary effluent from IPWWTPs. The Mn-based catalyst/O3 system achieved 84.8%, 69.8%, and 86.4% removals of COD, TOC, and UV254, which were 3.3, 5.7, and 1.1 times that in ozonation alone, respectively. Moreover, the Mn-based catalytic ozonation process exhibited excellent pH tolerance ranging from pH 4.0 to 9.0. Additionally, the depth analysis based on fluorescence excitation-emission matrix (EEM) confirmed that the catalytic ozonation process preferred to degrade toxic aromatic hydrocarbons. The existence of the Mn-based catalyst/O3 system enhanced 21.4%–38.3% more fluorescent organic matters removal, compared to that in ozonation alone. Mechanistic studies proved that the abundant Lewis acid sites (Mnn+/Mn(n+1)+ and adsorbed oxygen) on the surface of the Mn-based catalyst effectively promoted O3 decomposition into reactive oxygen species (ROS), and ·O2‒/HO2· and 1O2 were the main ROS for degrading refractory organic contaminants. The contributions of ROS oxidation (91.2%) was much higher than that of direct O3 oxidation (8.8%). Thus, this work provides an effective advanced treatment process for purifying secondary effluent from IPWWTPs.

In the process of biomass chemical looping gasification using calcium ferrite as an oxygen carrier, H2O or CO2 can be injected into the oxidation reactor to produce H2 or CO with high purity while oxidizing the reduced oxygen carrier, which is a new technology that has attracted wide attention in recent years. However, the splitting reaction mechanism of H2O or CO2 is still unclear. Therefore, based on density functional theory (DFT) calculations, the adsorption behavior of H2O and CO2, the electronic structure, and the splitting reaction path of H2O and CO2 on the surface of the reduced CaFe2O4 were systematically studied to deeply understand the re-action mechanism. The results show that H2O and CO2 form stable complexes on the CaO(1 1 1)/Fe(1 1 0) surface by chemisorption. H2O is splitted to H2 and adsorbed O* through a two-step reaction. In this process, the step of H2O cracking to HO* and H* is the rate-determining step. CO2 is splitted into CO* and O* through a one-step reaction, in which the desorption of CO from the surface is a rate-determining step. The total charges of H2O and CO2 after adsorption are -0.313 |e| and -1.086 |e|, respectively, and the total charges of Fe atoms on the surface are 0.444 |e| and 0.265 |e|, respectively. H2O and CO2 are electron acceptors, and Fe atoms on the surface are electron donors. The splitting of H2O or CO2 and the oxidation of reduced oxygen carriers are generally exothermic reactions, which can realize the oxidation of the reduced oxygen carrier and provide heat for the system.

Nitrate electrocatalytic reduction (NO3RR) is a potential approach to ammonia (NH3) production, and the limited NH4+–N selectivity and NH4+–N yield rate are great challenges in NO3RR to NH3. Herein, the self-supported iron phosphide electrodes were successfully prepared by electrodeposition and low-temperature pyrolysis method. The characterization results shown that 0.2FexP/Fe0-300 electrode consisted of amorphous FexP and crystalline Fe0 particles. 0.2FexP/Fe0-300 electrode exhibited the good NO3RR performance with high NO3−–N removal efficiency of 96.04

The chemical looping gasification (CLG) kinetics of biochars with calcium ferrite as oxygen carriers and the effects of different kinds of calcium ferrite and biochars were investigated by TGA. The properties of biochars and calcium ferrite were analyzed by XRD, SEM, BET, etc. The Škvára-Šesták method was used to determine the kinetic mechanism function. The results show that the reduction reaction rate and the oxygen carrying capacity of oxygen carriers follow the sequence: Ca2Fe2O5 > CaFe2O4 > Fe2O3, and CaFe2O4 > Ca2Fe2O5 > Fe2O3, respectively. The oxygen carriers can be completely reduced to Fe and CaO by biochar. The activation energy of CaFe2O4 reduction is in the range of 167.44–600.83 kJ/mol; and the activation energy of Ca2Fe2O5 reduction is in the range of 413.62–583.51 kJ/mol. The CaFe3O5 generated during the reduction of CaFe2O4 may have a negative influence on the lattice oxygen diffusion. The reduction of CaFe2O4 can be divided into two stages: when the conversion degree α is less than 0.15, the CaFe2O4 is reduced to Ca2Fe2O5 following the random nucleation and nuclei growth model; when α is greater than 0.15, Ca2Fe2O5 is further reduced to CaO and Fe following the 3-D diffusion mechanism. The mechanism function of the reduction of Ca2Fe2O5 is the same as that of the second stage of CaFe2O4 reduction.

Wet torrefaction (WT) is an effective biomass upgrading technology that has recently received widespread attention. However, the effects of WT on the physicochemical properties and gasification behaviors of biochar remain unclear, which limits the practical application of WT biomass as a fuel for gasification. In this study, hydrochar was prepared from corn stalk (CS) and poplar sawdust (PS) by a batch reactor. Then, biochar was prepared by rapid pyrolysis of hydrochar in a fixed-bed reactor. The physicochemical structure and gasification characteristics of fuel were studied. It was found that the AAEMs content in WT biochar was significantly reduced. The contents of K and Mg in biochar were reduced by more than 90 % and the contents of Ca were reduced by more than 75 % compared with the raw biochar. Below 220 degrees C, the graphitization degree of biochar increased with WT temperature. The specific surface area of CS char increased after WT, while the PS char decreased. The gasification reactivity of biochar decreased dramatically with the increase of WT temperature, and the time required for complete gasification increased obviously. The random pore model (RPM) has a satisfactory fitting on biochar gasification behavior. Therefore, RPM can be used to predict the biochar gasifi-cation behavior for other gasification temperatures. Activation energy of WT biochar is increased and the gasification reactivity is decreased compared with the raw biochar. The gasification activation energy of WT biochar for CS and PS were 225.80-285.59 kJ/mol and 146.39-264.25 kJ/mol, respectively. The research on the gasification kinetics of WT biochar can provide very important information for the reasonable design and operation of the gasifier.

P and N co-doped Fe SACs with dual reaction sites exhibited an ultra-low activation energy and exhibited excellent BPA degradation efficiency in the PMS-based heterogeneous Fenton-like reaction.

A heterogeneous Fenton-like catalyst with single redox site has a rate-limiting step in oxidant activation, which limited its application in wastewater purification. To overcome this, a bimetallic doping strategy was designed to prepare a heterogeneous Fenton-like catalyst (Fe-Mo/rGO) with a double-reaction center. Combined with electrochemical impedance spectroscopy and density functional theory calculation, it was confirmed that the formation of an electron-rich Mo center and an electron-deficient Fe center through the constructed Fe-O-Mo and Mo-S-C bonding bridges induced a higher electron transfer capability in the Fe-Mo/rGO catalyst. The designed Fe-Mo/rGO catalyst exhibited excellent sulfamethazine (SMT) degradation efficiency in a broad pH range (4.8–8.4). The catalytic performance was hardly affected by inorganic anions (Cl−, SO42− and HCO3−) in the complicated and variable water environment. Compared to Fe/rGO and Mo/rGO catalysts, the SMT degradation efficiency increased by about 14.6 and 1.6 times in heterogeneous Fenton-like reaction over Fe-Mo/rGO catalyst. The electron spin resonance and radical scavenger experiments proved that ·O2−/HO2· and 1O2 dominate the SMT removal in the Fe-Mo/rGO/H2O2 system. Fe and Mo, as active centers co-supported on rGO, significantly enhanced the electron transfer between catalyst, oxidant, and pollutants, which accelerated the reactive oxygen species generation and effectively improved the SMT degradation. Our findings offer a novel perspective to enhance the performance of heterogeneous Fenton-like catalysts by accelerating the electron transfer rate in the degradation of organic pollutants.

随着MBR的广泛应用,为控制膜污染导致高运行成本问题,优化新型平板膜MBR的曝气条件成为目前的一个研究热点.本研究通过使用CFD Fluent软件,结合多相流模型和湍流模型进行超薄平板膜MBR的高质量流态模拟,量化膜面剪切力,并从流场及膜污染角度分别对3种气水比(10∶1、15∶1和20∶1)工况下的MBR进行了优化分析,选择出超薄平板膜MBR的最优气水比.研究结果表明,膜片之间的流速分布均存在中间大、两侧小的不均匀性,且单个膜面剪切力分布与MBR流态特征密切相关,膜面颗粒沉积概率与剪切力均值呈负相关;对比了以0.1m·s-1为临界流速的不同曝气下的流场形态分布特性,并综合考虑曝气能耗及膜面冲刷,确定3种气水比中的最优值为15∶1.

Corn straw was torrefied under different temperatures and pressures to verify the influence of gas pressure on the torrefaction of biofuel. The torrefied products were characterized by proximate analysis, ultimate analysis, FT-IR, TGA and pyrolysis experiments. The results indicate that the deoxidation efficiency and energy density of torrefied products under both atmospheric pressure (AP) and gas pressured (GP) conditions increase with the increase of torrefaction temperature. The temperature required for GP torrefaction is almost 40 °C lower than that for AP torrefaction to obtain the same mass yield. The energy yield, carbon yield, deoxidation efficiency and the energy density of GP-torrefied corn straw are 1.125, 1.142, 1.539 and 1.131 times higher than those of AP-torrefied one, respectively. The GP-torrefied samples show better hydrophobicity and are easier to dehydrate. In addition, the pyrolysis of GP-torrefied corn straw produces significantly higher fractions of CH 4 and H 2 in the gaseous product than the pyrolysis of AP-torrefied one. Meanwhile, the relative content of phenols in the liquid products for the pyrolysis of GP-torrefied samples increases up to 51.11%, whereas the contents of furans and acids decrease considerably. The results suggest that GP torrefaction performs better in biofuel upgrading than AP torrefaction under the same temperature.

The emergence of organophosphorus flame retardants and the efficient removal from aquatic environments have aroused increasing concerns. The Urea functionalized Fe3O4@LDH (Urea-Fe3O4@LDH) was prepared and used to adsorb triphenyl phosphate (tphp) for the first time. The tphp adsorption capacity was up to 589 mg g-1, and the adsorption rate reached 49.9 mg g-1 min-1. Moreover, the influences of various environmental factors (pH, ionic strength and organic matter) on the tphp adsorption on the Urea-Fe3O4@LDH were investigated. The initial pH of the solution significantly affected the tphp adsorption, whereas the ionic strength and HA slightly affected the adsorption. The main adsorption mechanism was attributed to electrostatic interaction and π-π interaction. We believe that urea is one of excellent functional groups for the tphp adsorption removal and the materials with urea groups as the adsorbents exhibit good prospects in the future.

Fe2O3–ZrO2 catalysts with different morphologies (nanoplates (HZNPs), nanorods (HZNRs), nanocubes (HZNCs), and nanotubes (HZNTs)) were prepared by a hydrothermal method to investigate the effect of the morphology on the catalytic performance in the Fenton-like reaction for sulfamethazine (SMT) degradation. The Fe2O3–ZrO2 catalysts were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (BET) analysis. The H2O2 adsorption and the Fe2+ density sites on the Fe2O3–ZrO2 catalysts had a close relationship with the morphologies and exhibited an important effect on the ·OH formation in the Fenton-like reaction. Free ·OH radicals were the main oxidative species in the reaction, and the normalized ·OH concentration per surface area of the catalysts was 4.52, 2.24, 2.20, and 0.37 μmol/m2 for HZNPs, HZNRs, HZNCs, and HZNTs, respectively. The Fe2O3–ZrO2 catalysts with different morphologies showed good catalytic performance, and the order of SMT degradation was HZNPs > HZNRs > HZNCs > HZNTs. Total SMT removal was achieved in the Fenton-like reaction over HZNPs at pH 3.0 and 45 °C after 240 min.

In this work, we adopted the method of doping Nb element to improve the photo response of MoS 2 . The experiment results show the responsivity of the Nb-doped MoS 2 sample is improved under red and purple light. When the wavelength is 650 nm and the bias voltage is 10 V, the photo responsivity of Nb-doped MoS 2 sample is 65 mA/W, while that of the MoS 2 sample is 0.05 mA/W. And this result can be explained by the higher absorbance of Nb-doped MoS 2 than pure MoS 2 calculated by first principles based on density functional theory. Besides, an interesting phenomenon has been discovered that at a voltage of less than 1V, the optical response of Nb-doped MoS 2 is completely opposite.