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•The progress of glycerol selective oxidation over noble metal catalyst is reviewed.•The effect of pH on the performance of noble metal catalyst is emphasized.•The properties of ...support affect the catalyst structure and consequent performance.•Structure and performance of catalyst are related to the metal-support interaction.•Structure and performance of catalyst are related to the metal-metal interaction.
Glycerol is a significant by-product of biodiesel production and a functional molecule with three hydroxyl groups. Glycerol can be transformed through different catalytic processes, among which the selective oxidation of glycerol over heterogeneous catalyst is appealing due to its environmental friendliness and the facile production of various value-added products from glycerol. Owing to the structural sensitivity of the reaction, the activity and products selectivity not only depend on the active metal sites, but also is affected by many other factors, such as the pH of the reaction system, the structure and characters of metal and support. This article provides a comprehensive review of recent developments on glycerol selective oxidation over supported noble metal catalysts. Critical attention is paid to the influence of metal-support and metal-metal interactions on the electronic and geometrical structure of catalysts and the consequent catalytic performances, which is conducive to better understanding of the reaction mechanism and more rational design of catalyst to enhance the catalytic activity and selectivity of desired products, such as 1,3-dihydroxyacetone.
Platinum-tin (Pt/Sn) binary nanoparticles are active electrocatalysts for the ethanol oxidation reaction (EOR), but inactive for splitting the C-C bond of ethanol to CO2. Here we studied detailed ...structure properties of Pt/Sn catalysts for the EOR, especially CO2 generation in situ using a CO2 microelectrode. We found that composition and crystalline structure of the tin element played important roles in the CO2 generation: non-alloyed Pt46-(SnO2)54 core-shell particles demonstrated a strong capability for C-C bond breaking of ethanol than pure Pt and intermetallic Pt/Sn, showing 4.1 times higher CO2 peak partial pressure generated from EOR than commercial Pt/C.
Abstract
Background
The hallmark of type 1 diabetes (T1D) is an absolute lack of insulin. However, many studies showed a tendency to heterogeneity in TID. We aimed to investigate the demographic and ...clinical characteristics in T1D and the differences in young-onset and adult-onset patients.
Methods
This retrospective study was conducted among 1943 patients with clinically diagnosed T1D. Medical records on patients’ demographics, anthropometric measurements, and clinical manifestation were collected. According to the age at onset, the newly diagnosed patients were divided into the young-onset group (< 18 years, 234 patients, mean age 11 years) and adult-onset group (≥ 18 years, 219 patients, mean age 27 years). Pancreatic β-cell function was assessed by fasting C-peptide (FCP) and 2-h C-peptide (2-h CP).
Results
The median age of patients at disease onset was 22 years. The median duration of patients was 3 years. The overall median glycated hemoglobin (HbA1c) value was 10.3 % 89(mmol/mol). The prevalence of diabetic retinopathy was 25.1 %. The overall rate of DKA at onset in the new-onset patients was 59.6 %. The frequency of overall dyslipidemia was 37.8 %. The most frequent dyslipidemia was low high-density lipoprotein-cholesterol (HDL) (29 %). The proportion of patients with anti-glutamic acid decarboxylase (GADA), insulin antibody (IAA) and islet cell antibody (ICA) were 28.1 %, 6.4 % and 21.6 %, respectively. The mean HbA1c showed a downward trend with age. Increasing or decreasing trends of overweight and obesity in this population during the period 2012 to 2018 was not found.
Compared with young-onset T1D, adult-onset patients comprised better islet function (FCP: 0.4 vs. 0.3 ng/ml,
P
< 0.001; 2-h CP: 0.9 vs. 0.7 ng/ml
P
< 0.001, respectively) and glycemic control 12.9 % (117mmol/mol) vs. 11.7 % (104mmol/mol),
P
< 0.001, higher prevalence of diabetes condition in the male gender (64.4 % vs. 51.3 %,
P
= 0.006), higher proportion of obesity or overweight (24.6 % vs. 9.5 %,
P
= 0.002), higher frequency of GADA (33.7 % vs. 23.3 %,
P
= 0.025), and lower frequency of diabetic ketoacidosis at disease onset (64.5 % vs. 43.5 %,
P
< 0.001).
Conclusions
This population was characterized by poor overall blood glucose control, high prevalence of DKA, dyslipidemia and diabetic retinopathy, and low prevalence of islet-related antibodies, and overweight or obesity. Adult-onset patients with T1D were not uncommon and had better clinical manifestations than young-onset patients. Any findings related to body mass index (BMI) and autoantibodies should be considered strictly exploratory due to excessive missing data.
Abstract
Catalytic reduction of CO
2
over Cu-based catalysts can produce various carbon-based products such as the critical intermediate CO, yet significant challenges remain in shedding light on the ...underlying mechanisms. Here, we develop a modified triple-stage quadrupole mass spectrometer to monitor the reduction of CO
2
to CO in the gas phase online. Our experimental observations reveal that the coordinated H
2
O on Cu(I)-based catalysts promotes CO
2
adsorption and reduction to CO, and the resulting efficiencies are two orders of magnitude higher than those without H
2
O. Isotope-labeling studies render compelling evidence that the O atom in produced CO originates from the coordinated H
2
O on catalysts, rather than CO
2
itself. Combining experimental observations and computational calculations with density functional theory, we propose a detailed reaction mechanism of CO
2
reduction to CO over Cu(I)-based catalysts with coordinated H
2
O. This study offers an effective method to reveal the vital roles of H
2
O in promoting metal catalysts to CO
2
reduction.
The electrocatalytic conversion of biomass into high-value-added chemicals is one of the effective methods of green chemistry. Conventional metal catalysts have disadvantages, such as low atomic ...utilization and small surface areas. Catalyst materials derived from metal–organic frameworks (MOFs) have received much attention due to their unique physicochemical properties. Here, an MOF-derived non-precious metal CoxNiyS electrocatalyst was applied to the oxidation of biomass-derivative 5-hydroxymethylfurfural (HMF). The HMF oxidation reaction activities were modulated by regulating the content of Co and Ni bimetals, showing a volcano curve with an increasing proportion of Co. When the Co:Ni ratio was 2:1, the HMF conversion rate reached 84.5%, and the yield of the main product, 2,5-furandicarboxylic acid (FDCA), was 54%. The XPS results showed that the presence of high-valent nickel species after electrolysis, which further proved the existence and reactivity of NiOOH, as well as the synergistic effect of Co and Ni promoted the conversion of HMF. Increasing the content of Ni could increase the activity of HMF electrochemical oxidation, and increasing the content of Co could reduce the increase in the anodic current. This study has important significance for designing better HMF electrochemical catalysts in the future.
A thermodynamic analysis of the oxidative steam reforming of glycerol (OSRG) for hydrogen production has been carried out with Aspen plus
TM. The reaction was investigated at ambient pressure within ...the carbon-to-oxygen (C/O) ratio of 0.5–3.0, steam-to-carbon (S/C) ratio of 0.5–8.0 and temperature of 400–850 °C. Higher C/O and S/C ratios favor the production of hydrogen from glycerol. The highest hydrogen selectivity is obtained at 600–700 °C. To predict the potential technical obstacles in the glycerol reforming process, the OSRG process was compared with oxidative steam reforming of ethanol (OSRE) in terms of hydrogen production, autothermal condition and carbon deposition. The selectivity to hydrogen via OSRG is lower than that via OSRE under identical conditions. To achieve autothermal reforming, higher S/C and C/O ratios are required for reforming of glycerol than for ethanol due to the higher oxygen content in a glycerol molecule. From the viewpoint of thermodynamics, the glycerol reforming is more resistant to the carbon deposition. On the basis of the thermodynamic analysis and the preliminary experimental study, suggestions were proposed to guide the development of the glycerol reforming technique.
► We analyzed the thermodynamics of the reforming of glycerol by Aspen plus
TM. ► The OSRG reaction should be performed at 600–700 °C with C/O ratio of 0.8–1.2. ► Higher coking resistance and lower hydrogen yield for glycerol than those for ethanol. ► The reforming of crude glycerol is highly desired for reducing refinery cost. ► The efficient catalyst is highly desired for the glycerol reforming.
The uptake of hexavalent chromium (Cr(VI)) ions from wastewater is of great significance for environmental remediation and resource utilization. In this study, a self‐designed instrument equipped ...with an oxidized mesoporous carbon monolith (o‐MCM) as an electro‐adsorbent is developed. o‐MCM with a super hydrophilic surface displayed a high specific surface area (up to 686.5 m2 g−1). With the assistance of an electric field (0.5 V), the removal capacity of Cr(VI) ions is as high as 126.6 mg g−1, much higher than that without an electric field (49.5 mg g−1). During this process, no reduction reaction of Cr(VI) to Cr(III) ions is observed. After adsorption, the reverse electrode with 10 V is used to efficiently desorb the ions on the carbon surface. Meanwhile, the in situ regeneration of carbon adsorbents can be obtained even after ten recycles. On this basis, the enrichment of Cr(VI) ions in a special solution is achieved with the assistance of an electric field. This work lays a foundation for the uptake of heavy metal ions from wastewater with the assistance of the electric field.
The efficient uptake of Cr(VI) ions from wastewater with the assistance of an electric field is achieved by using a self‐designed instrument equipped with an oxidized mesoporous carbon monolith as an electro‐adsorbent. The in situ regeneration of carbon adsorbents and the enrichment of Cr(VI) ions in a special solution is obtained with the assistance of an electric field.
Environmentally friendly and energy saving treatment of black liquor (BL), a massively produced waste in Kraft papermaking process, still remains a big challenge. Here, by adopting a NiCaOCa12Al14O33 ...bifunctional catalyst derived from hydrotalcite-like materials, we demonstrate the feasibility of producing high-purity H2 (∼96%) with 0.9 mol H2 mol−1 C yield via the sorption enhanced steam reforming (SESR) of BL. The SESRBL performance in terms of H2 production maintained stable for 5 cycles, but declined from the 6th cycle. XRD, Raman spectroscopy, elemental analysis and energy dispersive techniques were employed to rationalize the deactivation of the catalyst. It was revealed that gradual sintering and agglomeration of Ni and CaO and associated coking played important roles in catalyst deactivation and performance degradation of SESRBL, while deposition of Na and K from the BL might also be responsible for the declined performance. On the other hand, it was demonstrated that the SESRBL process could effectively reduce the emission of sulfur species by storing it as CaSO3. Our results highlight a promising alternative for BL treatment and H2 production, thereby being beneficial for pollution control and environment governance in the context of mitigation of climate change.
H2 production with 96% purity and 0.9 mol H2 mol−1 C yield was achieved by sorption-enhanced steam reforming of black liquor over a NiCaOCa12Al14O33 bi-functional catalyst, the sulfur removal was also realized by storing it as CaSO3. Display omitted
An auto-thermal micro-reformer was fabricated to produce hydrogen from ethanol–water mixture. The reformer employed an Ir/La₂O₃ catalyst supported on ceramic foam. The effect of ceramic foam ...materials, including Al₂O₃, SiC and ZrO₂, on the performance of the micro-reformer was investigated. The optimal catalytic activity and hydrogen selectivity were achieved over the ZrO₂ loaded catalyst. The strong interaction between the ceramic ZrO₂ foam and the catalyst results in the reduction of the Ir particle size, which significantly improves the ethanol reforming activity, hydrogen selectivity and catalyst stability. The resistance to vibration and the stability of the reformer during the repeated start-up and shut-down (RSS) operation were studied. The reformer can be auto-thermally started-up within ∼90s. During a continuous operation, the reformer produces 3.1mol H₂ per mol ethanol with a hydrogen flow rate of ∼0.41m³/h, which can feed a H₂–O₂ fuel cell at the level of ∼765W. These results demonstrate the potential application of the proposed reformer in the portable distributed hydrogen source.
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