Tuning the oxidation state and reducibility of Co species is crucial for enhancing the catalytic performance of Cobased catalysts in the ethanol steam reforming (ESR) reaction. Here, two Co/CeO2 catalysts are synthesized from Co(NO3)2.6H2O (Co/CeO2-N) and CoCl2.6H2O (Co/CeO2-C) precursors to enhance hydrogen-production efficiency. Catalytic tests show that Co/CeO2-N exhibits superior performance, achieving complete ethanol conversion (100 %) and a high H2 yield of 68.0 % at 500 degrees C. X-ray diffraction (XRD) and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) of CO chemisorption demonstrate higher Co dispersion in Co/ CeO2-N than in Co/CeO2-C. X-ray photoelectron spectroscopy (XPS) and H2 temperature programmed reduction (H2-TPR) studies reveal that Co/CeO2-N possesses a lower oxidation states and improved reducibility of Co species, originating from an electronic metal-support interaction (EMSI) that facilitates electron donation from the CeO2 support to Co. We ascribe this EMSI to the weakened Co-nitrate interactions after low-temperature nitrate decomposition. In situ DRIFTS analysis of the ESR reaction further confirms preferential formation of C1 compounds over Co/CeO2-N, consistent with its optimized lower Co oxidation states. This work establishes a rational precursor-mediated strategy to tune the oxidation state of Co via EMSI, thus enabling efficient hydrogen production.

Ammonia production remains energy-intensive and high carbon emission through conventional processes, making the conversion of aqueous nitrate pollutants into ammonia a "waste-to-wealth" strategy. Current nitrate treating methods including photocatalysis and electrocatalysis are respectively limitted by light shielding effect and complex electrode fabrication. Here we propose a novel and efficient microwave catalytic approach for nitrate to ammonia conversion using a Pd-dispersed fiber-structured ZnFe2O4@Carbon@MoS2 (Pd-FCM) catalyst, demonstrating remarkable efficiency even with a household-microwave-oven. This approach achieves an exceptional ammonia yield rate of 20.04 mmol h- 1 L- 1 and a total ammonia yield of 5.52 mmol, outperforming most photocatalytic and electrocatalytic approaches. This exceptional catalytic performance stems from the synergistic effects of ZnFe2O4@Carbon's microwave absorption, MoS2's nitrate adsorption, and the activation energy reduction by Pd nanoclusters. Our work advances sustainable nitrogen management by integrating wastewater denitrification with green ammonia synthesis, contributing to the circular nitrogen economy and sustainable development goals.

Developing a high-efficiency catalyst for the selective hydrogenation of acetylene to ethylene is of great importance for industrial polyethylene production to remove acetylene impurities. In this work, a passivation strategy for palladium catalyst has been developed by inducing strong electron metal-support interaction (EMSI) between the loaded Pd nanocatalyst and the nitrogen-containing metal-organic framework (MOF) support (ZIF-8-dia) to substantially improve the catalytic performance. Catalytic hydrogenation of acetylene demonstrates that the Pd/ZIF-8-dia exhibits ethylene selectivity above 83%, whether ethylene is cofed with acetylene and hydrogen or not. Mechanism studies reveal that the convenient transformation of Zn-N into Pd-N strengthens the EMSI to form a Pd nanocatalyst with a positively charged surface, substantially lowers its activity for hydrogen activation and the hydrogenation reaction, and favors the desorption of ethylene from the catalyst surface, therefore improving the performance of the ZIF-supported Pd catalyst for selective acetylene hydrogenation. The passivation strategy developed in this work opens up an opportunity for developing high-performance Pd catalysts for selective acetylene hydrogenation.

Modulating electronic structure to improve photocarriers (photo-generated electrons and holes) separation and suppress photocarriers recombination is crucial for developing highly-active g-C3N4 photocatalyst to degrade tetracycline for alleviating environmental pollution. In this work, a highly disordered g-C3N4 catalyst with abundant carbon defects has been developed via optimization of the precursor composition. The g-C3N4-M1C2, prepared by pyrolysis of mixed melamine/cyanuric acid precursors with the molar ratios of 1:2, possesses more sensitive photocurrent response, lower recombination of photocarriers and more negative potential of conduction band as compared to other g-C3N4 catalysts. These enhance the photocarrier-production efficiency and promote the formation of superoxide radicals, thus boosting the photocatalytic tetracycline degradation performance. During a 90-min tetracycline degradation reaction catalyzed by g-C3N4-M1C2, the degradation ratio reaches about 87.0 %, demonstrating a substantial improvement in photocatalytic performance as compared to other investigated g-C3N4 catalysts (g-C3N4-M, g-C3N4-C and g-C3N4-M2C1, which are prepared by pyrolysis of melamine, cyanuric acid and mixed melamine/cyanuric acid precursors with the molar ratios of 2:1, respectively). This work opens up new opportunity of developing high-performance g-C3N4 catalysts by modulating electronic structure through optimization of precursor composition.

Developing highly efficient catalysts for carbon dioxide reduction reaction (CO2RR) to convert CO2 into carbon-based chemicals and reduce anthropogenic carbon emissions is desirable but challenging. In this work, a high-activity NiNC-2mIM catalyst has been developed via pyrolysis of 2-methylimidazole (2mIM) Ni-zeolite-imidazolate-framework (ZIF) precursor, it exhibits excellent performance for CO2 reduction producing carbon monoxide (CO), with Faradaic efficiency for CO (FECO) of about 98% and a current density of 55 mAu00B7cmu22122 at u22121.0 V (vs. reversible hydrogen electrode (RHE)), outperforming the investigated NiNC-IM and NiNC-2eIM (derived from imidazole Ni-ZIF precursor and 2-ethylimidazole Ni-ZIF precursor, respectively) in this work and many previously reported Ni-based nanocatalysts. Mechanism studies demonstrate that 2-methylimidazole ligand induces higher content of pyridinic N species in the NiNC-2mIM catalyst, which enhances the affinity for CO2 and provides low-polarity and high-activity Niu2013N motif for CO2RR. This work develops a novel imidazole-based ZIF mediated regulation strategy for engineering pyridinic N-rich N-doped carbon supported Ni nanocatalyst to highly efficiently catalyze CO2 reduction producing CO.

Enhancing charge-separation efficiency and suppressing recombination of photoexcited carriers are the key to photocatalysts. In this work, a novel solvothermal strategy has been developed to regulate the structure of BiOBr catalysts, three BiOBr catalysts are prepared by solvothermal procedure using water, ethanol and ethylene glycol as the solvents, and denoted as BiOBr-W, BiOBr-ET and BiOBr-EG, respectively. Among them, the BiOBr-EG exhibits substantially improved catalytic activity for tetracycline degradation. Catalyst characterizations reveal that the BiOBr-EG possesses high specific surface area, more oxygen vacancies and an electron-rich surface. High photocurrent response and low photoluminescence (PL) intensity indicate enhanced charge-separation efficiency and suppressed recombination of photogenerated electron-hole pairs. The low conduction-band potential of BiOBr-EG favors production of superoxide free radicals and tetracycline degradation. This work opens up new opportunities for developing high-performance BiOBr catalysts by structure regulation to improve charge separation efficiency and suppress the recombination of photogenerated electron-hole pairs in photocatalysis.

Developing high-activity non-noble metal catalyst to replace high-cost Pt-based catalyst to catalyze hydrogen evolution reaction (HER) is desirable but challenging for industry-level hydrogen production from water splitting. Molybdenum carbide (Mo2C) possesses Pt-like d-band structure, however, its HER performance is far away from that of Pt-based catalyst. In this work, a threshold carbonization strategy is developed to substantially upgrade the intrinsic activity of Mo2C catalyst for electrochemical HER. The prepared Mo2C-700 catalyst exhibits overpotential of as low as 90 mV for achieving current density of 10 mA/cm2 in alkaline electrolyte and excellent catalytic durability, being close to Pt-based catalyst and outperforming most reported Mo2C-based catalysts. Mechanism studies demonstrate that threshold carbonization reaction of MoO3 with H2/CH4 at 700 °C substantially inhibits the formation of carbon deposits and leads to more exposed Mo sites and hydroxyl groups on the surface of Mo2C-700 catalyst, thus endowing the Mo2C-700 catalyst with superhydrophilic and superaerophobic surface to facilitate water adsorption and H2 bubbles release. Density functional theory calculations reveal that the less carbon deposits on Mo2C catalyst surface upgrades the Mo d-band center toward Fermi level, substantially enhances the capacity of water adsorption, decreases the energy barrier of water dissociation reaction, and furthermore, results in near-zero hydrogen adsorption Gibbs free energies on Mo2C catalyst, thus endowing Mo2C-700 exceptional activity for alkaline HER.

Developing a high-activity and low-cost catalyst to reduce the anodic overpotential is essential for hydrogen production from water splitting. In this work, a hetero-structured Co7Fe3/Mo2C@C catalyst has been developed to efficiently catalyze oxygen evolution reaction (OER), the overpotential (ƞ10) of Co7Fe3/Mo2C@C-catalyzed OER with current density of 10 mA/cm2 is about 254 mV, substantially lower than the counterparts of Co7Fe3@C-catalyzed OER (ƞ10, 308 mV) and Mo2C@C-catalyzed OER (ƞ10, 439 mV), close to that of OER catalyzed by commercial RuO2. The mechanistic studies reveal that the distinct electron transfer across the Co7Fe3/Mo2C interface results in electron-deficient Co7Fe3, which has been identified as the highly active catalytic sites. Density functional theory (DFT) calculations manifest that Mo2C induces a distinct decrease in electron density on Co7Fe3 and upgrades the d-band centers of Co and Fe in Co7Fe3 towards Fermi energy level, thus substantially lowering the energy barrier of the rate-determining reaction step and conferring significantly improved OER activity on the Co7Fe3/Mo2C@C catalyst.

The imperative role of formaldehyde (HCHO) intermediates in the formation of aromatics during the methanol-to-hydrocarbons process has drawn extensive interest. Herein, using synchrotron radiation photoionization mass spectrometry (SR-PIMS) combined with a near-ambient pressure reactor, abundant critical intermediates including HCHO along with oxygenated species (C1-C4 carbonyl compounds, alpha,beta-unsaturated aldehydes, and cyclopentenones) and polyunsaturated hydrocarbons (dienes, polyenes, and fulvene) were identified during the methanol-to-aromatics reaction over Zn-modified HZSM-5. HCHO derived from the direct dehydrogenation of methanol was proved to noticeably promote aromatic selectivity. With the assistance of C-13-labeled HCHO cofeeding, a detailed HCHO-mediated monocyclic and polycyclic aromatic formation network involving Prins, hydroacylation, and aldol condensation reactions of HCHO was proposed. This proposed mechanism provides profound insight into multiple roles of HCHO intermediates via oxygenate-based routes and reveals the fate of the oxygen atom in methanol conversion over zeolite catalysts.

Nitrate reduction reaction (NO3RR) is deemed a promising pathway for both ammonia synthesis and water purification. Developing a high-efficiency catalyst with excellent NH3 selectivity and catalytic stability is desirable but remains challenging. In this work, a dendritic copper oxide catalyst (Cu-B2) has been developed to efficiently catalyze NO3RR for ammonia production, the Cu-B2 exhibits excellent catalytic performance, achieving an NH3 Faradaic efficiency as high as 94 % and an NH3 yield of 16.9 mg h-1 cm-2 with a current density of 192.3 mA cm-2 at - 0.6 V (vs. RHE, reversible hydrogen electrode). During NO3RR testing, the Cu-B2 catalysts are reduced in situ to form highly active Cu0/Cu+ sites, while retaining its dendritic morphology. Compared with other catalysts, the Cu-O bond in Cu-B2 catalyst has weaker polarity, resulting in Cu0/Cu+ sites in lower oxidation states. In situ attenuated total reflection surface enhanced infrared absorption spectroscopy (ATR-SEIRAS) studies reveal the Cu-B2 catalyst exhibits a potential-independent capability for *NO3 - adsorption and high conversion efficiency of NO2- intermediate into ammonia, DFT calculations reveal that Cu-B2 exhibts higher NO3 - adsorption energy and lower NO3 - adsorption energy barrier than Cu-B1, thus endowing it with a remarkably improved catalytic activity and durability.

Tuning the metal-support interaction is a general strategy of regulating the chemical state of catalytic active site for high-efficiency hydrogen production from ethanol steam reforming (ESR) reaction. In this work, a Co catalyst supported on the Si4Al2O2N6 solid solution of Si3N4 and Al2O3 (Co/Si4Al2O2N6) has been developed to effectively catalyze ESR reaction. Our results demonstrate that the Co/Si4Al2O2N6 catalyst exhibits remarkably improved performances as compared with the Co/Si3N4 and Co/Al2O3 catalysts. In the Co/Si4Al2O2N6-catalyzed ESR reaction, ethanol conversion of 97 % has been achieved with hydrogen yield reaching 73 %. Long-time catalytic experiment manifests the Co/Si4Al2O2N6 catalyst possesses excellent durability. X-ray photoelectron spectroscopy (XPS) studies reveal that the enhanced metal-support interaction (MSI) and charge transfer from Si4Al2O2N6 support to Co species in the Co/Si4Al2O2N6 catalyst confer lower valence state on the Co catalyst supported on Si4Al2O2N6, thus promoting the C-C bond cleavage capability, leading to high C1 product yield and boosting the hydrogen-production efficiency. The catalytic mechanism studies explored by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) reveal that the Co/Si4Al2O2N6 exhibits a remarkable preference for C1 products over the Co/Si3N4 and Co/Al2O3 catalysts at low reaction temperature, thus resulting in high hydrogen-production efficiency with excellent catalytic durability.

As the highly stable and abundant carbon source in nature, the activation and conversion of CO2 into high-value chemicals is highly desirable yet challenging. The development of Cu(I)/Cu(II)& horbar;N tri-site synergistic single-atom catalysts (TS-SACs) with remarkable CO2 activation and conversion performance is presented, eliminating the need for external additives in cascade reactions. Under mild conditions (40 degrees C, atmospheric CO2), the catalyst achieves high yields (up to 99%) of valuable 2-oxazolidinones from CO2 and propargylamine. Notably, the catalyst demonstrates easy recovery, short reaction times, and excellent tolerance toward various functional groups. Supported by operando techniques and density functional theory calculations, it is elucidated that the spatially proximal Cu(I)/Cu(II)& horbar;N sites facilitate the coupling of multiple chemical transformations. This surpasses the performance of supported isolated Cu(I) or Cu(II) catalysts and traditional organic base-assisted cascade processes. These Cu(I)/Cu(II)& horbar;N tri-site synergistic atom active sites not only enable the co-activation of CO2 at the Cu(II)& horbar;N pair and alkyne at the Cu(I) site but also induce a di-metal locking geometric effect that accelerates the ring closure of cyclic carbamate intermediates. The work overcomes the limitations of single metal sites and paves the way for designing multisite catalysts for CO2 activation, especially for consecutive activation, tandem, or cascade reactions.

α-Fe2O3/epoxy resin composite superhydrophobic coating was prepared with α-Fe2O3 nanoparticles and epoxy resin by spin coating method.The coating without epoxy resin has higher contact angle(CA)and lower ice adhesion strength(IAS),but the mechanical properties are poor.The α-Fe2O3/epoxy resin composite superhydrophobic coating exhibits good mechanical durability.In addition,compared with the bare aluminum substrate,the Ecorr of the composite coating is positive and the Jcorr is lower.The inhibition efficiency of the composite coating is as high as 99.98%in 3.5 wt%NaCl solution.The difference in the microstructure caused by the two preparation methods leads to the changes in mechanical properties and corrosion resistance of composite superhydrophobic coating.

培养本科生创新理念和创新能力是新时期高等教育的重要任务.实验的多维度开放机制包括观念开放、时空开放、师资开放.引导本科生提升创新能力训练的途径有:利用拓展性教学实验、参与教师实际科研课题、参加创新性研究项目和学科竞赛等.实验开放机制保障、师资队伍保障和学科研究平台保障等方面为实验的多维度开放提供了全方位的保障,可以切实提高矿物加工专业本科生创新能力.

To explore the catalytic cracking mechanism of CuO on oil shale and the catalytic activity of surface modifications of CuO on oil shale, dimethyl sulfoxide (C2H6OS) is used as a model molecule representative of organic sulfur compounds in oil shale, and the adsorption and dissociation behaviors of C2H6OS molecules on pure and OH pre-adsorbed CuO(111) surfaces were investigated by density functional theory calculations. The results indicate that C2H6OS selectively adsorbs at the Cusub sites via the S atom and decomposes through cleavage of the C–H bond prior to the breaking of the C-S bond on both surfaces. The presence of OH on the CuO(111) surface promoted the dissociation of C2H6OS. The energy barriers of dehydrogenation and desulfurization of C2H6OS on the OH pre-adsorbed CuO(111) surface were 20.0 and 19.3 kcal/mol, respectively, which are 41% and 49% lower than those on pure surfaces. The present results provide crucial guidance for the synthesis and improvement of high-performance pyrolysis catalysts specifically designed for oil shale applications. Additionally, they also present important data regarding to the thermal stability of C2H6OS in the presence of incompatible substances.

Prompt production of bismuth subcarbonate (Bi2O2CO3) intermediate is crucial for high-efficiency formate production and preservation of the bismuth-oxygen (Bi-O) structures during electrochemical CO2 reduction re-action (CO2RR) catalyzed by Bi-based catalyst. In this work, we investigate the CO2RR performance of bismuth oxyhalide (BiOX, including BiOCl, BiOBr and BiOI) catalysts with nanosheet-assembling microsphere morphology and develop an effective strategy of engineering BiOI-derived Bi2O2CO3 through dynamic ion ex-change reaction to promote formate production from CO2RR. Among investigated BiOX catalysts with nanosheet-assembling microsphere morphology, BiOI exhibits the highest ion exchange rate due to the large interlayer spacing and low binding energy between [Bi2O2]2+ layer and I- ion. The produced BiOI-derived Bi2O2CO3 in-herits the large interlayer spacing of BiOI and thus facilitates diffusion of HCO3- ions to promote CO2RR for formate production. By comparison with BiOCl and BiOBr, BiOI exhibits better CO2RR performance, achieving faradaic efficiency of 98 % with a current density of 42.0 mA cm- 2 and excellent long-term durability. Mech-anism studies demonstrate that the sufficient supply of HCO3- ions resulted from large interlayer spacing of BiOI-derived Bi2O2CO3 significantly promotes formate production and, in turn, improves the resistance of Bi-O structures to electroreduction. This work provides a deep insight into the mechanism of BiOX-catalyzed CO2RR for formate production, opening up new opportunities for developing high-performance CO2RR catalysts.

以黄铜矿为原料,采用高温焙烧处理制备铜基催化剂用于催化甲醇水蒸气重整制氢反应,借助X射线粉末衍射仪、场发射扫描电子显微镜、H2 程序升温还原、甲醇水蒸气重整制氢试验以及原位漫反射傅里叶变换红外光谱仪等对所制催化剂进行表征.结果表明,改变焙烧温度可调节铜基催化剂中铜位点的配位结构,黄铜矿在800℃下焙烧所得催化剂的催化性能最佳.

Chitosan is an environmentally friendly biomolecule with great potential for application in metal corrosion protection. First, Chitosan benzaldehyde schiff base (CTSB) and 8-hydroxyquinoline functionalized chitosan benzaldehyde schiff base (HQ-CTSB) were synthesized from chitosan, benzaldehyde, and 8-hydroxyquinoline as high-efficiency and environment-friendly corrosion inhibitors. The structures of the synthesized products were characterized by infrared spectroscopy. The corrosion of N80 steel was tested using electrochemical measurements and analysis by varied concentrations of CTSB and HQ-CTSB in a hydrochloric acid solution. The PDP results confirmed that both CTSB and HQ-CTSB corrosion inhibitors were mixed corrosion inhibitors. Furthermore, the EIS findings revealed that the corrosion inhibition efficiency of the two inhibitors was 87.11% and 98.52% at 800 mg/L, respectively. According to SEM and XPS analyses, the CTSB and HQ-CTSB molecules bonded to the surface of N80 steel and formed a surface protective layer. Density functional theory (DFT) calculations showed that CTSB and HQ-CTSB have multiple active sites that may become adsorbent on the metal surface. And molecular dynamics (MD) simulations showed that corrosion inhibitors CTSB and HQ-CTSB lie flat on the surface of Fe(110). The theoretical calculation agreed well with the experimental results.

Twelve kinds of 8-hydroxyquinoline derivatives were synthesized and characterized. The weight loss method was used to evaluate their inhibition efficiencies (IEs) in a 1.0 M HCl solution at 333 K. The results showed that the alkyl chain length, heteroatoms (S, N, and O), and number of benzene rings significantly affect the IE. Herein, the IE of 5-[(dodecylthio)methyl]-8-quinolinol reached 98.71%. Meanwhile, the potentiodynamic polarization results indicated that all 8-hydroxyquinoline derivatives were mixed-type inhibitors. Electrochemical impedance spectroscopy results revealed that 8-hydroxyquinoline derivatives can increase polarization resistance, supporting their adsorption on the N80 steel surface. Moreover, according to density functional theory (DFT), the frontier orbital distribution and quantum chemical parameters (EHOMO, ELUMO, dipole moment μ, etc.) were calculated, and the results confirmed that the substituents of protonated 8-hydroxyquinoline derivatives significantly influenced the frontier orbital distribution. Molecular dynamics simulation illustrated that all protonated 8-hydroxyquinoline derivatives were adsorbed parallel to the Fe(110) surface, and the interaction energy (Eint) evidenced that the molecular size would affect their strength of adsorption on the Fe(110) surface. The linear and nonlinear quantitative structure-activity relationship models were established by linear regression (LR) methods and BP neural networks (NN), respectively. The LR model was established by using Eint and μ, and the coefficient of determination (R2) was 0.934. In addition, the nonlinear NN model was obtained according to IE and all parameters (DFT parameters and Eint). Then, the two calculation inhibition efficiencies (IEcal) were obtained from the LR and NN models, and the R2 values of the linear correlation between the IEcal and the experimental IE were 0.940 and 0.951, respectively. In addition, the IE of the tested inhibitor was 51.86% and the IEcal values predicted by the LR and NN models were 52.68% and 53.06%, respectively. Our results demonstrate that both the LR and NN models have good fits and predictive ability.

Silicon nitride (Si 3 N 4 ) supported cobalt catalysts (Co/Si 3 N 4 ) were fabricated by using wetness impregnation procedure.The microscopic morphology,phase composition,and electronic states were characterized by XRD,TEM,SEM,and XPS,respectively.For comparison,cobalt catalyst supported on SiO 2 (Co/SiO 2 ) was also investigated.XPS studies and DFT calculations show that the cobalt species in Co/Si 3 N 4 have lower valence state than those in Co/SiO 2 .The catalytic ESR reactions demonstrate that Co/Si 3 N 4 exhibits distinctly higher catalytic activity and hydrogen selectivity than Si 3 N 4 support and Co/SiO 2 catalyst with the identical cobalt loading,indicative of the favorable effect of Si 3 N 4 support on the catalytic performance of supported cobalt catalyst.Durability tests and TG-DSC studies show that Co/Si 3 N 4 catalyst exhibits better stability and resistance to coke during the same catalytic experiment period.