Electron Deficient Ir-O Bonds Promote Heterogeneous Ir-Catalyzed Anti-Markovnikov Hydroboration of Alkenes under Mild Neat Conditions.

Tuning electronic characteristics of metal-ligand bonds based on reaction pathways to achieve efficient catalytic processes has been widely studied and proven to be feasible in homogeneous catalysis, but it is scarcely investigated in heterogeneous catalysis. Herein, we demonstrate the regulation of the electronic configuration of Ir-O bonds in an Ir single-atom catalyst according to the borane activation mechanism. Ir-O bonds in Ir1/Ni(OH)x are found to be more electron-poor than those in Ir1/NiOx. Despite the mild solvent-free conditions and ambient temperature, Ir1/Ni(OH)x exhibits outstanding performance for the hydroboration of alkenes, furnishing the desired alkylboronic esters with a turnover frequency value of ≤3060 h-1 and 99% anti-Markovnikov selectivity, which is significantly better than that of Ir1/NiOx (42 h-1). It is further proven that the more electron-poor Ir-O bonds as active centers are more oxidative and so benefit the activation of the H-B bond in the reductive pinacolborane.

Serum immunoglobulin concentrations and risk of type 2 diabetes mellitus in adults: a prospective cohort study from the TCLSIH study.

Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by hyperglycemia resulting from defects in insulin secretion and/or insulin action. Increasing evidence suggests that inflammation played an important role in the pathogenesis of T2DM. Prospective studies on the link between immunoglobulins concentrations and the risk of T2DM in adults are limited. We developed a cohort study including 7,093 adults without T2DM history. The incidence of T2DM was 16.45 per 1,000 person-years. Compared with the lowest quartiles, the hazard ratios (95% confidence intervals) of T2DM for the highest quartiles of IgG, IgE, IgM and IgA were 0.64 (0.48-0.85), 0.94 (0.72-1.23), 0.68 (0.50-0.92) and 1.62 (1.24-2.11) (P for trend was < 0.01, 0.84, 0.02 and < 0.0001), respectively, suggesting that serum IgG and IgM concentrations were inversely associated with the incidence of T2DM, and IgA levels were positively associated with the risk of T2DM in a general adult population.

Ultrafast Unidirectional On-Chip Heat Transfer.

Effective and rapid heat transfer is critical to improving electronic components' performance and operational stability, particularly for highly integrated and miniaturized devices in complex scenarios. However, current thermal manipulation approaches, including the recent advancement in thermal metamaterials, cannot realize fast and unidirectional heat flow control. In addition, any defects in thermal conductive materials cause a significant decrease in thermal conductivity, severely degrading heat transfer performance. Here, the utilization of silicon-based valley photonic crystals (VPCs) is proposed and numerically demonstrated to facilitate ultrafast, unidirectional heat transfer through thermal radiation on a microscale. Utilizing the infrared wavelength region, the approach achieves a significant thermal rectification effect, ensuring continuous heat flow along designed paths with high transmission efficiency. Remarkably, the process is unaffected by temperature gradients due to the unidirectional property, maintaining transmission directionality. Furthermore, the VPCs' inherent robustness affords defect-immune heat transfer, overcoming the limitations of traditional conduction methods that inevitably cause device heating, performance degradation, and energy waste. The design is fully CMOS compatible, thus will find broad applications, particularly for integrated optoelectronic devices.

Adherence to a healthy sleep pattern and risk of urologic cancers: A large prospective cohort study.

OBJECTIVE: A variety of unhealthy sleep behaviors have been shown to be associated with an increased risk of urologic cancers. However, little is known about the association between the overall sleep patterns and urologic cancers. To prospectively investigate the associations between a healthy sleep pattern and the risks of urologic cancers, including bladder cancer (BCa) and renal cell carcinoma (RCC). METHODS: In this prospective cohort study, 377,144 participants free of cancer at baseline were recruited from the UK Biobank. Data on sleep behaviors were collected through questionnaires at recruitment. The incident urologic cancer cases were determined through linkage to national cancer and death registries. We established a healthy sleep score according to five sleep traits (sleep duration, chronotype, insomnia, snoring, and daytime sleepiness). Cox proportional hazard regression models were used to calculate the adjusted hazard ratios and 95% confidence intervals to assess the relationship between the healthy sleep score and the risk of urologic cancers. RESULTS: During a median of ≥9 years of follow-up, we identified 1986 incident urologic cancer cases, including 1272 BCa cases and 706 RCC cases. Compared with the participants with a poor sleep pattern (score of 0-2), the multivariable-adjusted hazard ratio and 95% confidence interval were 0.85 (0.75 to 0.96) for urologic cancers, 0.80 (0.68 to 0.93) for BCa, and 0.91 (0.74, 1.12) for RCC, respectively, for those with the healthier sleep pattern (score of 4-5). CONCLUSION: Our results indicate that a healthy sleep pattern is associated with lower risks of urologic cancers.

Adherence to a healthy lifestyle including sleep and sedentary behaviors and risk of metabolic dysfunction-associated steatotic liver disease in Chinese adults.

OBJECTIVE: Various lifestyle factors including smoking, alcohol, physical activity, sedentary behavior, diet quality, sleep behavior, and overweight have been related to metabolic dysfunction-associated steatotic liver disease (MASLD); however, their joint impact on risk of MASLD is not well known. We prospectively investigated the association between a combination of lifestyle factors and risk of MASLD. METHODS: This prospective cohort study included 13,303 participants (mean age: 39.1 ± 11.3 years, female: 60.1%) in China. A novel healthy lifestyle score was created combining seven healthy factors: not smoking, no alcohol intake, regular physical activity, short sedentary time, healthy diet, healthy sleep, and healthy weight. Incident MASLD cases were ascertained annually by liver ultrasound and cardiometabolic risk factors. Multivariable Cox proportional hazards regression models were used to estimate the association of healthy lifestyle score with risk of MASLD. RESULTS: Within 48,036 person-years of follow-up, 2823 participants developed MASLD. After adjusting for age, sex, education, occupation, household income, personal and family history of disease, and total energy intake, compared with participants with 0-2 healthy lifestyle factors, the multivariable hazard ratios (95% confidence interval) of MASLD were 0.81 (0.73, 0.89), 0.67 (0.61, 0.75), and 0.55 (0.49, 0.62) for healthy lifestyle score of 3, 4, and 5-7, respectively (P for trend <0.0001). Such associations were consistent across subgroup and sensitivity analyses. CONCLUSION: Our results indicate that a higher healthy lifestyle score is associated with a lower risk of MASLD.

Longitudinal association between soft drink consumption and handgrip strength in adults: a prospective analysis from the Tianjin Chronic Low-Grade Systemic Inflammation and Health (TCLSIH) cohort study.

Soft drink consumption has become a highly controversial public health issue. Given the pattern of consumption in China, sugar-sweetened beverage is the main type of soft drink consumed. Due to containing high levels of fructose, a soft drink may have a deleterious effect on handgrip strength (HGS) due to oxidative stress, inflammation and insulin resistance. However, few studies show an association between soft drink consumption and HGS in adults. We aimed to investigate the association between soft drink consumption and longitudinal changes in HGS among a Chinese adult population. A longitudinal population-based cohort study (5-year follow-up, median: 3·66 years) was conducted in Tianjin, China. A total of 11 125 participants (56·7 % men) were enrolled. HGS was measured using a handheld digital dynamometer. Soft drink consumption (mainly sugar-containing carbonated beverages) was measured at baseline using a validated FFQ. ANCOVA was used to evaluate the association between soft drink consumption and annual change in HGS or weight-adjusted HGS. After adjusting for multiple confounding factors, the least square means (95 % CI) of annual change in HGS across soft drink consumption frequencies were -0·70 (-2·49, 1·09) for rarely drinks, -0·82 (-2·62, 0·97) for < 1 cup/week and -0·86 (-2·66, 0·93) for ≥ 1 cup/week (Pfor trend < 0·05). Likewise, a similar association was observed between soft drink consumption and annual change in weight-adjusted HGS. The results indicate that higher soft drink consumption was associated with faster HGS decline in Chinese adults.

The diagnostic value of serum YKL-40 for myocardial involvement in immune-mediated necrotising myopathy.

OBJECTIVES: This study aimed to determine the diagnostic value of YKL-40 for myocardial involvement in immune-mediated necrotising myopathy (IMNM). METHODS: We retrospectively analysed the data of patients with IMNM admitted to the Neurology Department at Tongji Hospital between April 2013 and August 2022. Clinical data including patients' demographics, clinical characteristics (disease duration, muscle strength, atrophy, rash, dysphagia, dyspnoea, and myalgia) and laboratory test results were collected from the electronic medical record system. Serum YKL-40 levels were measured using an enzyme-linked immunosorbent assay. A receiver operating characteristic (ROC) curve was drawn, and the area under the ROC curve was calculated to evaluate the diagnostic value of YKL-40 for cardiac involvement in IMNM. RESULTS: 29 patients with IMNM and15 sex and age-matched volunteers without history of heart diseases were recruited for the study. Compared with the healthy controls, serum YKL-40 levels were notably up-regulated [96.3 (55.5 120.6) pg/ml versus 19.6 (13.8 20.9) pg/ml; p=0.000] in patients with IMNM. We compared 14 patients with IMNM with cardiac abnormalities and 15 patients with IMNM without cardiac abnormalities. The most important finding was that serum YKL-40 levels were higher in the patients with IMNM with cardiac involvement based on cardiac magnetic resonance (CMR) examination [119.2 (88.4 185.69) pm/ml versus 72.5 (35.7 98) pm/ml; p=0.002]. YKL-40 had a specificity and sensitivity of 86.7% and 71.4% respectively, at a cut-off value of 105.46 pg/ml for predicting myocardial injury in patients with IMNM. CONCLUSIONS: YKL-40 could be a promising non-invasive biomarker for diagnosing myocardial involvement in IMNM. However, larger prospective study is warranted.

Non-negligible Toxicity to Fish in the Early Life Stages Triggered by Aqueous Leachate of Takeaway Plastic Containers.

Ordering takeout is a growing social phenomenon and may raise public health concerns. However, the associated health risk of compounds leaching from plastic packaging is unknown due to the lack of chemical and toxicity data. In this study, 20 chemical candidates were tentatively identified in the environmentally relevant leachate from plastic containers through the nontargeted chemical analysis. Three main components with high responses and/or predicted toxicity were further verified and quantified, namely, 3,5-di-tert-butyl-4-hydroxycinnamic acid (BHC), 2,4-di-tert-butylphenol (2,4-DTBP), and 9-octadecenamide (oleamide). The toxicity to zebrafish larvae of BHC, a degradation product of a widely used antioxidant Irganox 1010, was quite similar to that of the whole plastic leachate. In the same manner, RNA-seq-based ingenuity analysis showed that the affected canonical pathways of zebrafish larvae were quite comparable between BHC and the whole plastic leachate, i.e., highly relevant to neurological disease, metabolic disease, and even behavioral disorder. Longer-term exposure (35 days) did not cause any effect on adult zebrafish but led to decreased hatching rate and obvious neurotoxicity in zebrafish offspring. Collectively, this study strongly suggests that plastic containers can leach out a suite of compounds causing non-negligible impacts on the early stages of fish via direct or parental exposure.

Design, synthesis and biological evaluation of Thiazolo[3, 2-a]Pyrimidine derivatives as novel RNase H inhibitors.

Targeting Ribonuclease H (RNase H) has been considered a viable strategy for HIV therapy. In this study, a series of novel thiazolo[3, 2-a]pyrimidine derivatives were firstly designed and synthesized as potential inhibitors of HIV-1 RNase H. Among these compounds, A28 exhibited the most potent inhibition against HIV-1 RNase H with an IC50 value of 4.14 µM, which was about 5-fold increase in potency than the hit compound A1 (IC50 = 21.49 µM). To gain deeper insights into the structure-activity relationship (SAR), a CoMFA model was constructed to yield reasonable statistical results (q2 = 0.658 and R2 = 0.969). Results from magnesium ion chelation experiments and molecular docking studies revealed that these thiazolopyrimidine inhibitors may exert their inhibitory activity by binding to an allosteric site on RNase H at the interface between subunits p51 and p66. Furthermore, this analog demonstrated favorable physicochemical properties. Our findings provide valuable groundwork for further development of allosteric inhibitors targeting HIV-1 RNase H.

Effect of depression and the antidepressant fluoxetine on osseointegration-A pre-clinical in vivo experimental study.

OBJECTIVE: The aim of this study was to explore the effect of depression and selective serotonin reuptake inhibitors on implant osseointegration and bone healing. METHODS: Forty-eight 6- to 8-week-old SPF Sprague-Dawley male rats were randomly divided into four groups: the Control group, the Fluoxetine group, the Depression group and the De&Flu group. The rats in the Depression group and the De&Flu group were subjected to a depression modelling process, and the rats in the Control group and the Fluoxetine group were raised normally. Then, a titanium implant was placed in the right tibia of each rat. In the Fluoxetine group and De&Flu group, fluoxetine was injected subcutaneously daily, while subcutaneously injecting physiological saline in the Control group and Depression group. Collecting serum from the rats used for ELISA. The surgical area was cut for microcomputed tomography and histology observation. RESULTS: After 12 weeks, bone mineral density was lower in the De&Flu group than in the Control group, Depression group and Fluoxetine group. Bone mineral density was also lower in the Depression group and the Fluoxetine group than in the Control group. The percentage of bone-implant contact (BIC%) in De&Flu rats was lower than in the Control, Depression and Fluoxetine groups. The BIC% in the Depression group and the Fluoxetine group was lower than in the Control group. CONCLUSIONS: Depression and fluoxetine negatively affect bone density and implant osseointegration independently, and this damaging effect is exacerbated when both factors are present. The mechanism may be related to the dysregulation of the hypothalamic-pituitary-adrenal axis and inflammation in the body.

Abnormalities of retinal function in type 2 diabetes mellitus patients without clinical diabetic retinopathy detected by multifocal electroretinogram.

OBJECTIVE: To study the changes of retinal function in type 2 diabetes mellitus(DM) patients without apparently diabetic retinopathy via multifocal electroretinogram. METHODS: Thirty-six type 2 DM patients (72 eyes) without visible diabetic retinopathy were selected as the experimental group, and thirty-five healthy subjects (70 eyes) were selected as the control group. All subjects were underwent multifocal electroretinogram (mf- ERG). RESULTS: Compared with the control group, the implicit time delay of the P1 wave in the first ring, third ring, fourth ring, and fifth ring of the experimental group was significant (t = -3.154, p = 0.004, t = -8.21, p = 0.000, t = -3.067, p = 0.004, t = -4.443, p = 0.000, respectively). The implicit time of the N1 wave in the fourth- and fifth-ring were also significantly delayed compared with the control group (t = -3.549, p = 0.001, t = 2.961, p = 0.005, respectively). Compared with the control group, the implicit time of the P1 wave and N1 wave in the temporal region of the experimental group were delayed (t = -2.148, p = 0.037, t = -2.834, p = 0.007, respectively). There were no significant difference between the experimental group and the control group of the temporal area in the amplitude density of P1 wave, N1 wave. There was no difference in the implicit time and amplitude density of the N1 and P1 waves in the nasal region between the experimental group and the control group. The multifocal electroretinogram complex parameters showed better specificity and sensitivity in the diagnosis of diabetic retinopathy. CONCLUSION: The multifocal electroretinogram can detect abnormal changes in the retina of type 2 DM patients without visible diabetic retinopathy. The multifocal electroretinogram complex parameter is a potential indicator for the early diagnosis of diabetic retinopathy.

Side-Opened Hollow Fiber-Based SPR Sensor for High Refractive Index Detection.

To facilitate the sensor fabrication and sensing operation in microstructured optical fiber-based surface plasmon resonance (SPR) sensors for high refractive index (RI) detection, we propose a special hollow fiber-based SPR sensor that comprises an opening on its body side and a thin gold layer coated on its outer surface. The analyte is able to flow into the hollow core through the side-opening to form new fiber core, with the Gaussian-like mode propagating in it. We investigate the sensing performance of the proposed sensor in a higher RI range of 1.48 to 1.54 at two feasible schemes: one is to only fill the fiber core with analyte (Scheme A), and the other is to directly immerse the sensor in the analyte (Scheme B). The results demonstrate that our sensor exhibits higher wavelength sensitivity at Scheme A with a maximum wavelength sensitivity of 12,320 nm/RIU, while a greater amplitude sensitivity was found at Scheme B with a maximum amplitude sensitivity of 1146 RIU-1. Our proposed sensor features the advantages of simple fabrication, flexible operation, easy analyte filling and replacing, enhanced real-time detection capabilities, high RI detection, and very high wavelength sensitivity and amplitude sensitivity, which makes it more competitive in SPR sensing applications.

Structure-Based Design of Novel Thiazolone[3,2-a]pyrimidine Derivatives as Potent RNase H Inhibitors for HIV Therapy.

Ribonuclease H (RNase H) was identified as an important target for HIV therapy. Currently, no RNase H inhibitors have reached clinical status. Herein, a series of novel thiazolone[3,2-a]pyrimidine-containing RNase H inhibitors were developed, based on the hit compound 10i, identified from screening our in-house compound library. Some of these derivatives exhibited low micromolar inhibitory activity. Among them, compound 12b was identified as the most potent inhibitor of RNase H (IC50 = 2.98 µM). The experiment of magnesium ion coordination was performed to verify that this ligand could coordinate with magnesium ions, indicating its binding ability to the catalytic site of RNase H. Docking studies revealed the main interactions of this ligand with RNase H. A quantitative structure activity relationship (QSAR) was also conducted to disclose several predictive mathematic models. A molecular dynamics simulation was also conducted to determine the stability of the complex. Taken together, thiazolone[3,2-a]pyrimidine can be regarded as a potential scaffold for the further development of RNase H inhibitors.

A scale for measuring nursing digital application skills: a development and psychometric testing study.

BACKGROUND: The adoption of digitization has emerged as a new trend in the advancement of healthcare systems. To ensure high-quality care, nurses should possess sufficient skills to assist in the digital transformation of healthcare practices. Suitable tools have seldom been developed to assess nurses' skills in digital applications. This study aimed to develop the Nursing Digital Application Skill Scale (NDASS) and test its psychometric properties. METHODS: The Nursing Digital Application Skill Scale was developed in three phases. In Phase 1, an item pool was developed based on previous literature and the actual situation of nursing work. Phase 2 included 14 experts' assessment of content validity and a focus group interview with 30 nurses to pretest the scale. In phase 3, 429 registered nurses were selected from March to June 2023, and item analysis, exploratory factor analysis, and confirmatory factor analysis were used to refine the number of items and explore the factor structure of the scale. Additionally, reliability was determined by internal consistency and test-retest reliability. RESULTS: The final version of the NDASS consisted of 12 items. The content validity index of NDASS reached 0.975 at an acceptable level. The convergent validity test showed that the average variance extracted value was 0.694 (> 0.5) and the composite reliability value was 0.964 (> 0.7), both of which met the requirements. The principal component analysis resulted in a single-factor structure explaining 74.794% of the total variance. All the fitting indices satisfied the standard based upon confirmatory factor analyses, indicating that the single-factor structure contributed to an ideal model fit. The internal consistency appeared high for the NDASS, reaching a Cronbach's alpha value of 0.968. The test-retest reliability was 0.740, and the split-half coefficient was 0.935. CONCLUSION: The final version of the NDASS, which possesses adequate psychometric properties, is a reliable and effective instrument for nurses to self-assess digital skills in nursing work and for nursing managers in designing nursing digital skill training.

Synergy of Single Atoms and Lewis Acid Sites for Efficient and Selective Lignin Disassembly into Monolignol Derivatives.

Lignin is the most abundant aromatic polymer from the natural and renewable lignocellulosic biomass resource. Developing highly efficient catalysts for lignin depolymerization to produce valuable monophenols with high yield and selectivity remains a desirable but challenging target in this field. Here, we design a synergistic catalyst combining atomically dispersed Mo centers and Al Lewis acid sites on a MgO substrate (Mo1Al/MgO) for the depolymerization of Eucalyptus lignin via the ß-aryl ether bond cleavage. A near-theoretical monophenol yield of 46% with an ultrahigh selectivity of 92% for coniferyl and sinapyl methyl ether, as well as good cycling durability, was achieved simultaneously by Mo1Al/MgO in an inert N2 atmosphere. First-principles calculations and control catalytic experiments confirmed the synergistic catalysis mechanism between Mo1-O5 single-atom centers and the neighboring Al Lewis acid sites with the participation of a methanol solvent. This study validates the feasibility of designing better-performing catalysts with synergistic multiactive sites for the efficient and selective disassembly of complex renewable biopolymers into highly value-added products with lower cost and greater security.

MOF-Derived Ru1Zr1/Co Dual-Atomic-Site Catalyst with Promoted Performance for Fischer-Tropsch Synthesis.

Cobalt-based catalysts have been widely used for Fischer-Tropsch synthesis (FTS) in industry; however, achieving rational catalyst design at the atomic level and thereby a higher activity and more long-chain-hydrocarbon products simultaneously remain an attractive and difficult challenge. The dual-atomic-site catalysts with unique electronic and geometric interface interactions offer a great opportunity for exploiting advanced FTS catalysts with improved performance. Herein, we designed a Ru1Zr1/Co catalyst with Ru and Zr dual atomic sites on the Co nanoparticle (NP) surface through a metal-organic-framework-mediated synthesis strategy which presents greatly enhanced FTS activity (high turnover frequency of 3.8 × 10-2 s-1 at 200 °C) and C5+ selectivity (80.7%). Control experiments presented a synergic effect between Ru and Zr single-atom site on Co NPs. Further density functional theory calculations of the chain growth process from C1 to C5 revealed that the designed Ru/Zr dual sites remarkably lower the rate-limiting barriers due to the significantly weakened C-O bond and promote the chain growth processes, resulting in the greatly boosted FTS performance. Therefore, our work demonstrates the effectiveness of dual-atomic-site design in promoting the FTS performance and provides new opportunities for developing efficient industrial catalysts.

Protein foods from animal sources and risk of nonalcoholic fatty liver disease in representative cohorts from North and South China.

BACKGROUND: Emerging evidence suggests that animal protein foods may increase the risk of nonalcoholic fatty liver disease (NAFLD). We therefore examined the NAFLD risk reduction related to substituting plant protein foods for animal protein foods. METHODS: The cohort in North China included 14,541 participants from the Tianjin Chronic Low-Grade Systemic Inflammation and Health (TCLSIH) study, and the cohort in South China included 1297 participants from the Guangzhou Nutrition and Health Study (GNHS). Dietary intake was assessed using validated food frequency questionnaires. NAFLD was ascertained by abdominal ultrasound. The Cox model was used to fit the substitution analysis. RESULTS: In the TCLSIH cohort, when replacing one type of animal protein food (eggs, processed meat, unprocessed red meat, poultry, and fish) with an equivalent serving of plant protein foods (nuts, legumes, and whole grains), the replacement of animal protein foods with whole grains showed the strongest benefit; substituting one serving per day of whole grains for an equal amount of eggs (hazard ratio [HR] = 0.89; 95% confidence interval [CI]: 0.79, 1.00), processed meat (HR = 0.76; 95% CI: 0.64, 0.91), unprocessed red meat (HR = 0.90; 95% CI: 0.81, 1.00), poultry (HR = 0.81; 95% CI: 0.72, 0.92), or fish (HR = 0.87; 95% CI: 0.78, 0.97) was associated with a lower risk of NAFLD. In both the TCLSIH and GNHS cohorts, replacing poultry with fish, nuts, legumes, or whole grains was associated with a lower risk of NAFLD. When different numbers of protein foods were simultaneously replaced, the risk reduction of NAFLD was stronger. CONCLUSIONS: Our findings suggest that replacing animal protein foods with plant protein foods is related to a significant reduction in NAFLD risk.

Metal Phosphorous Chalcogenide: A Promising Material for Advanced Energy Storage Systems.

The development of efficient and affordable electrode materials is crucial for clean energy storage systems, which are considered a promising strategy for addressing energy crises and environmental issues. Metal phosphorous chalcogenides (MPX3 ) are a fascinating class of two-dimensional materials with a tunable layered structure and high ion conductivity, making them particularly attractive for energy storage applications. This review article aims to comprehensively summarize the latest research progress on MPX3 materials, with a focus on their preparation methods and modulation strategies. Additionally, the diverse applications of these novel materials in alkali metal ion batteries, metal-air batteries, and all-solid-state batteries are highlighted. Finally, the challenges and opportunities of MPX3 materials are presented to inspire their better potential in energy storage applications. This review provides valuable insights into the promising future of MPX3 materials in clean energy storage systems.

WO3 -Assisted Synergetic Effect Catalyzes Efficient and CO-Tolerant Hydrogen Oxidation for PEMFCs.

Developing anode catalysts with substantially enhanced activity for hydrogen oxidation reaction (HOR) and CO tolerance performance is of great importance for the commercial applications of proton exchange membrane fuel cells (PEMFCs). Herein, an excellent CO-tolerant catalyst (Pd-WO3 /C) has been fabricated by loading Pd nanoparticles on WO3 via an immersion-reduction route. A remarkably high power density of 1.33 W cm-2 at 80 °C is obtained by using the optimized 3Pd-WO3 /C as the anode catalyst of PEMFCs, and the moderately reduced power density (73% remained) in CO/H2 mixed gas can quickly recover after removal of CO-contamination from hydrogen fuel, which is not possible by using Pt/C or Pd/C as anode catalyst. The prominent HOR activity of 3Pd-WO3 /C is attributed to the optimized interfacial electron interaction, in which the activated H* adsorbed on Pd species can be effectively transferred to WO3 species through hydrogen spillover effect and then oxidized through the H species insert/output effect during the formation of Hx WO3 in acid electrolyte. More importantly, a novel synergetic catalytic mechanism about excellent CO tolerance is proposed, in which Pd and WO3 respectively absorbs/activates CO and H2 O, thus achieving the CO electrooxidation and re-exposure of Pd active sites for CO-tolerant HOR.

Inserting Single-Atom Zn by Tannic Acid Confinement To Regulate the Selectivity of Pd Nanocatalysts for Hydrogenation Reactions.

Precisely controlling the selectivity of nanocatalysts has always been a hot topic in heterogeneous catalysis but remains difficult owing to their complex and inhomogeneous catalytic sites. Herein, an effective strategy to regulate the chemoselectivity of Pd nanocatalysts for selective hydrogenation reactions by inserting single-atom Zn into Pd nanoparticles is reported. Taking advantage of the tannic acid coating-confinement strategy, small-sized Pd nanoparticles with inserted single-atom Zn are obtained on the O-doped carbon-coated alumina. Compared with the pure Pd nanocatalyst, the Pd nanocatalyst with single-atom Zn insertion exhibits prominent selectivity for the hydrogenation of p-iodonitrobenzene to afford the hydrodeiodination product instead of nitro hydrogenation ones. Further computational studies reveal that the single-atom Zn on Pd nanoparticles strengthens the adsorption of the nitro group to avoid its reduction and increases the d-band center of Pd atoms to facilitate the reduction of the iodo group, which leads to enhanced selectivity. This work provides new guidelines to tune the selectivity of nanocatalysts with guest single-atom sites.