Search Results (1,539)

Herein, motivated by the excellent redox properties of rod-shaped ceria (CeO₂-NR), a series of TM/CeO₂ catalysts, employing the first-row 3d transition metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) as active metal phases, were comparatively assessed under identical synthesis and reaction conditions to decipher the role of active metal in the CO₂ hydrogenation process. Notably, a volcano-type dependence of CO₂ hydrogenation activity/selectivity was disclosed as a function of metal entity revealing a maximum for the Ni-based sample. Ni/CeO₂ is extremely active and fully selective to methane (Y_CH4 = 90.8% at 350 °C), followed by Co/CeO₂ (Y_CH4 = 45.2%), whereas the rest of the metals present an inferior performance. No straightforward relationship was disclosed between the CO₂ hydrogenation performance and the textural, structural, and redox properties, whereas, on the other hand, a volcano-shaped trend was established with the relative concentration of oxygen vacancies and partially reduced Ce³⁺ species. The observed trend is also perfectly aligned with the previously reported volcano-type dependence of atomic hydrogen adsorption energy and CO₂ activation as a function of 3d-orbital electron number, revealing the key role of intrinsic electronic features of each metal in conjunction to metal–support interactions. Full article

To improve the electrochemical activity and discharge performance of an aluminum-air (Al-air) battery, a commercial 6061 alloy (Al6061) was selected as the anode, and CeO₂ was also added inside the anode to enhance its performance. The CeO₂/Al6061 composite was prepared using selective laser melting (SLM) technology. The influence of hatch spacing on the forming quality, corrosion resistance, and discharge performance of the anode was studied in detail. The results showed that with an increase in hatch spacing, the density, corrosion resistance, and discharge performance of the anode first increased and then decreased. When the hatch spacing is 0.13 mm, the anode has the best forming quality. At this point, the density reaches 98.39%, and the self-corrosion rate (SCR) decreases to 2.596 × 10⁻⁴ g·cm⁻²·min⁻¹. Meanwhile, the anode exhibits its highest electrochemical activity and discharge voltage, which is up to −1.570 V. The change in anode performance is related to the defects generated during the SLM forming process. For samples with fewer defects, the anode can dissolve uniformly, while for samples with more defects, the electrode solution is prone to penetrate the defects, causing uneven corrosion and reducing electrochemical and discharge activity. Full article

This study examines the impact of gender diversity in the positions of board commissioners, executive directors, and audit committee members on the financial performance of firms experiencing financial trouble. It also evaluates whether the presence of a CEO with multiple responsibilities moderates this relationship. The analysis encompassed 224 publicly traded companies from the non-financial sector, spanning the years 2012 to 2021. The study employed the dynamic panel model system GMM to address issues of endogeneity, simultaneity, and heterogeneity in the data. The findings indicate that the presence of women on supervisory boards and in senior positions has a substantial impact. Companies with a higher number of female board members have reduced financial hardship among Malaysian listed enterprises. Female directors exhibit a greater level of caution and risk aversion while participating in management choices, which is a significant conclusion. Research indicates that the majority of financial variables are inherently endogenous, so dynamic models are better suited for analyzing the interaction between these variables. This study also presents the notable correlation between gender diversity on boards of management, CEO duality, and financial difficulty. Full article

Mono- and di-substituted cerium oxide catalysts, viz. Ce_0.95Cu_0.05O_2-δ, Ce_0.90Cu_0.10O_2-δ, Ce_0.90 Cu_0.05Mn_0.05O_2-δ, Ce_0.85Cu_0.10Mn_0.05O_2-δ, and Ce_0.80Cu_0.10Mn_0.10O_2-δ, were synthesized via a one-step urea-assisted solution combustion method. The elemental composition and textural and structural properties of the catalysts were determined by various physical, electronic, and chemical characterization techniques. Hydrogen temperature-programmed reduction showed that co-doping of copper and manganese ions into the CeO_2-δ lattice improved the reducibility of copper. Powder XRD, XPS, HR-TEM, and Raman spectroscopy showed that the catalysts were a singled-phased, solid-solution metal oxide with a cerium oxide cubic fluorite (cerianite) structure, and evidence of oxygen vacancies was observed. Catalytic results in the preferential oxidation of CO in a hydrogen-rich stream showed that complete CO conversion occurred between 150 and 180 °C. Furthermore, at 150 °C, Ce_0.90Cu_0.05Mn_0.05O_2-δ, Ce_0.90 Cu_0.10O_2-δ, and Ce_0.85Cu_0.10Mn_0.05O_2-δ catalysts were the most active, achieving complete CO conversion and CO₂ selectivity of 81, 79, and 71%, respectively. The catalysts performed moderately in the presence of CO₂ and water, with the Ce_0.90Cu_0.05Mn_0.05O_2-δ catalyst giving a CO conversion of 80% in CO₂, which decreased to about 60% when water was added. Full article

It is important to improve the separation ability of photogenerated electrons and the adsorption capacity of carbon dioxide (CO₂) for efficient photoreduction of CO₂. Here, we synthesized ZnCdS quantum dots (ZCS-QDs) and cerium dioxide nanosheets (CeO₂) using the solvothermal method and calcination method. We combined CeO₂ and ZCS-QDs to effectively enhance the charge separation efficiency, and the lifetime of photogenerated electrons was increased 4.5 times. The CO evolution rate of the optimized composite (ZCS-QDs/CeO₂) was up to 495.8 μmol g⁻¹ h⁻¹, and it had 100% product selectivity. In addition, the stability remained high after five cycles. The CO₂ adsorption capacity of the catalyst surface was observed by in situ FTIR. The test results showed that improving CO₂ capture ability and promoting photogenic electron separation had positive effects on enhancing photoreduction of CO₂. This study provides a reference for constructing a zero-dimensional–two-dimensional (0D–2D) heterojunction and explores potential CO₂ reduction reaction mechanisms. Full article

The catalytic applications of micron Cu powder are limited due to its large particle size and small specific surface area. Modifying micro-Cu powder to achieve a high catalytic performance is a challenge in the application of micron copper. In this work, micro-Cu was used to synthesize a CeO₂–Cu catalyst, and the phase composition and surface pore structure were analyzed using XRD, BET, etc. The CO₂ hydrogenation performance of the CeO₂–Cu catalyst was analyzed in comparison with CeO₂ and Cu, and we found that the CeO₂–Cu catalyst exhibited a synergistic effect between Cu and cerium, resulting in a much higher hydrogenation performance at 500 °C than CeO₂ or Cu alone. H₂-TPR and TEM characterization revealed that the CeO₂–Cu catalyst formed interfacial interactions with a relatively large Ce–Cu interface, where cerium oxide could promote the reduction of CuO and lower the reduction temperature. Additionally, cerium oxide formed a confinement structure for Cu, and the CeO₂–Cu catalyst exhibited a higher oxygen vacancy concentration, thereby promoting the CO₂ hydrogenation performance. Cu–CeO₂ interaction provides valuable insights into the catalytic application of micron Cu powder. Full article

While there has been a steady stream of research on chief technology officers (CTOs), studies specifically examining the expanding role of CTOs, particularly in the areas of environmental, social, and governance (ESG), remain scarce. Despite extensive research on boards of directors (BODs), chief executive officers (CEOs), and corporate social responsibility (CSR) committees, there is a significant lack of research on the role of CTOs in integrating ESG considerations into technology development and operations. To fill this gap, this study investigated the impact of CTO characteristics (personal, positional, and career-related) on corporate ESG performance. Based on previous studies, we created a conceptual model and proposed 12 hypotheses. A sample of 218 publicly traded corporations in Korea was selected, and a structural equation model was used to test the fit of the research model and hypotheses. The results indicate that the positional characteristics of the CTO positively affect a corporation’s ESG performance, whereas the career-related characteristics of the CTO negatively affect it. However, personal characteristics did not exhibit significant effects. Therefore, this study underscores the need for corporations to empower technology leaders, such as the CTO, and enable them to play an important role in strategic decision-making. By doing so, organizations can enhance their social responsibility, improve environmental sustainability, and maintain competitiveness. Full article

The present study presents the results obtained from evaluating the photocatalytic behavior of a series of sulfated CeO₂ materials in the photocatalytic degradation of the herbicide 2,4-dichlorophenoxyacetic acid. The CeO₂ photocatalytic support was prepared using the precipitation synthesis method. Subsequently, the support was wetly impregnated with different contents of sulfate ions (0.5, 1.0, and 2.0 wt.%). The materials were characterized using X-ray diffraction, nitrogen physisorption, infrared spectroscopy, diffuse reflectance UV–Vis spectrophotometry, and thermal analysis. The characterization results showed that the sulfation of the material promoted an increase in the surface area and a decrease in the average size of the crystallites. Likewise, it was possible to demonstrate the surface sulfation of the support through bidentate coordination of the sulfate groups to the semiconductor metal. Concerning photoactivity, the convenience of the surface modification of CeO₂ was confirmed because the sulfate groups acted as capturers of the electrons generated during the photocatalytic process, reducing the frequency of recombination of the charge carriers and allowing the availability of the gaps to favor the degradation reaction of the contaminant. Finally, it was evident that a percentage of 1.0 wt.% of the sulfate anion is the optimal content to improve the photocatalytic properties of CeO₂. Full article

The face of corporate governance is changing as new technologies in the scope of artificial intelligence and data analytics are used to make better future-oriented decisions on performance management. This study attempts to provide empirical results to analyze when the impact of diversity on the board of directors is most evident through the multi-breaks model and artificial neural networks. The input data for the simulation includes 853 electronic companies listed on the Taiwan Stock Exchange from 2000 to 2021. The empirical results show that the higher the percentage of female board members, the more influential the company’s performance is, which is only evident when the company is in good business condition. By integrating ANNs with multi-breakpoint regression, this study introduces a novel approach to management research, providing a detailed perspective on how board diversity impacts firm performance across different conditions. The ANN results show that using the number of business board members for predicting Return on Assets yields the highest accuracy, with female board members following closely in predictive effectiveness. The presence of women on the board contributes positively to ROA, particularly when the company is experiencing favorable business conditions and high profitability. Our analysis also reveals that a higher percentage of male board members improves company performance, but this benefit is observed only in highly favorable and unfavorable business conditions. Conversely, a higher percentage of business members tends to affect performance during periods of high profitability negatively. The power of the board of directors and significant shareholders is positively correlated with performance, whereas CEO power positively impacts performance only when it is not extremely low. Independent board members generally do not have a significant effect on profits. Additionally, the company’s asset value positively influences performance primarily when the return on assets is high, and increased financial leverage is associated with reduced profitability. Full article

To improve the discharge performance of aluminum–air batteries, CeO₂/Al6061 composites were prepared as an anode using selective laser melting (SLM). Response surface methodology (RSM) was employed, and the test results were linearly fitted. A prediction model for the forming quality of the composite anode was established, and the reliability of the model and the interaction between process parameters were explored based on variance analysis and significance testing. On this basis, with corrosion potential, self-corrosion rate, and discharge voltage as optimization objectives, the optimal solution set of the SLM forming CeO₂/Al6061 anode process parameter was solved through a genetic algorithm, and experimental verification was conducted. The results indicate that the optimal process range for the forming quality and various properties of composite materials is laser power of 265~285 W, scanning speed of 985~1025 mm/s, and scanning spacing of 0.116~0.140 mm. The optimized process parameters were selected for reliability testing, and the errors were all within 3.0%, verifying the accuracy and reliability of the model. Full article

Nitrobenzene (NB) is one of the nitro-aromatic compounds that is extensively used in various chemical industries. Despite its potential applications, NB is considered to be a toxic compound that has significant hazardous effects on human health and the environment. Thus, it can be said that the NB level should be monitored to avoid its negative impacts on human health. In this vein, the electrochemical method has emerged as one of the most efficient sensing techniques for the determination of NB. The sensing performance of the electrochemical techniques depends on the electro-catalytic properties and conductivity of the electrode materials. In the past few years, various electrode materials, such as conductive metal ions, semiconducting metal oxides, metal–organic frameworks, and two-dimensional (2D) materials, have been used as the electrode material for the construction of the NB sensor. Thus, it is worth summarizing previous studies on the design and synthesis of electrode materials for the construction of the NB sensor. In this mini-review article, we summarize the previous reports on the synthesis of various advanced electrode materials, such as platinum (Pt) nanoparticles (NPs), silver (Ag) NPs, carbon dots (CDs), graphene, graphitic carbon nitride (g-C₃N₄), zinc stannate (ZnSnO₃), cerium oxide (CeO₂), zinc oxide (ZnO), and so on. Furthermore, the impacts of different electrode materials are systematically discussed for the sensing of NB. The advantages of, limitations of, and future perspectives on the construction of NB sensors are discussed. The aim of the present mini-review article is to enhance the knowledge and overall literature, working towards the construction of NB sensors. Full article

The impact of corporate governance mechanisms has been examined directly and independently, considering that such characteristics compete to explain environmental, social, and governance (ESG) performance. However, the nexus may be more complex than that suggested by most scholars, and more research is needed. This study applied a fuzzy-set qualitative comparative analysis to a sample of Spanish-listed companies in 2018–2020 to explore how good governance practices interact with CEO profiles to promote corporate sustainability practices. Our analysis discovered the importance of establishing sustainability committees and identified five pathways shaping governance practice bundles. Specifically, listed companies with a high code of good governance (GGC) compliance and a sustainability committee improve high ESG performance globally and for each ESG dimension. Furthermore, the effect is more relevant than the effect of the CEO profile, requiring either CEO duality (pathway 1) or extended CEO tenure (pathway 2). Concurrently, findings indicate three CEO profile configurations for GGC-neutral firms, providing companies with more flexibility in CEO selection. Two suggest that younger CEOs with longer tenure tend to be more motivated to engage in the G and S pillars (pathways 3 and 5). The third indicates that CEOs of older age and early tenure improve the E pillar (pathway 4). Full article

In this study, Ce₂[Zr_1−x(Ba_1/3Nb_2/3)_x]₃(MoO₄)₉ (0.02 ≤ x ≤ 0.1, CZ_1−xN_x) ceramics were sintered at 600 °C and 700 °C using the traditional solid-state method. An analysis conducted through XRD and Rietveld refinement confirmed that all the CZ_1−xN_x ceramics displayed a single phase with a trigonal structure (space group R-3c). The observed increases in cell volume with increasing x values indicate the successful substitution of (Ba_1/3Nb_2/3)⁴⁺. The high densification of the synthesized phase was validated by the density and SEM results. Additionally, the P-V-L theory demonstrates a strong correlation between the Ce-O bond and ε_r, as well as τ_f, and between the Mo-O bond and Q×f. Notably, the CZ_0.98N_0.02 ceramics demonstrated superior performance at 675 °C, exhibiting ε_r = 10.41, Q×f = 53,296 GHz, and τ_f = −23.45 ppm/°C. Finally, leveraging CZ_0.98N_0.02 ceramics as substrate materials enabled the design of a patch antenna suitable for the 5G communication band, demonstrating its significant potential in this field. Full article

Persistent homology is a powerful tool for quantifying various structures, but it is equally crucial to maintain its interpretability. In this study, we extracted interpretable geometric features from the persistent diagrams (PDs) of scanning transmission electron microscopy (STEM) images of self-assembled Pt-CeO₂ nanostructures synthesized under different annealing conditions. We focused on PD quadrants and extracted five interpretable features from the zeroth and first PDs of nanostructures ranging from maze-like to striped patterns. A combination of hierarchical clustering and inverse analysis of PDs reconstructed by principal component analysis through vectorization of the PDs highlighted the importance of the number of arc-like structures of the CeO₂ phase in the first PDs, particularly those that were smaller than a characteristic size. This descriptor enabled us to quantify the degree of disorder, namely the density of bends, in nanostructures formed under different conditions. By using this descriptor along with the width of the CeO₂ phase, we classified 12 Pt-CeO₂ nanostructures in an interpretable way. Full article

The growing presence of women at the top of companies has sparked interest in examining their role in the remuneration gap between senior managers and employees. This article analyses the traditional Chief Executive Officer (CEO)-to-employee pay ratio but includes a new relation, the senior-management-to-employee pay ratio, and extends the research by including six positions for women in company management: on the board of directors, executive directors, CEOs, proprietary directors, independent directors, and senior managers. The study is based on a sample of 77 listed companies in Spain from 2015 to 2022 and the panel data models have been estimated using the Generalised Method of Moments (GMM). The main findings indicate that the proportion of women in different categories of board and senior management positions has a positive effect on the CEO-to-employee pay ratio, especially in companies with higher market capitalisation. In contrast, the proportion of women in senior management positions has a negative effect on the CEO-to-employee pay ratio in all the samples analysed. Government agencies should prioritise the participation of women in non-board senior management positions in order to at least reduce the pay gap between senior managers and employees. Full article