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This article critically evaluates the influence of solution combustion synthesis (SCS) metrics on the properties of the synthesized product. Special attention is paid to photocatalytic applications of SCS-synthesized products.

Carbon materials have been widely used as microwave susceptors in many chemical processes because they are highly effective at transforming incoming electromagnetic energy for local (hot spot) heating. This property raises the intriguing possibility of using the all-pervasive carbonaceous deposits in operating heterogeneous catalytic processes to augment the catalytic performance of microwave-initiated reactions. Here, the catalytic activities of a range of carbon materials, together with carbon residues produced from a "test" reaction-the dehydrogenation of hexadecane under microwave-initiated heterogeneous catalytic processes, have been investigated. Despite the excellent microwave absorption properties observed among these various carbons, only activated carbons and graphene nanoplatelets were found to be highly effective for the microwave-initiated dehydrogenation of hexadecane. During the dehydrogenation of hexadecane on a Fe/SiC catalyst, active carbon species were formed at the early stage of the reactions but were subsequently transformed into filamentous but catalytically inert carbons that ultimately deactivated the operating catalyst.

Well-geometric-confined yolk-shell catalysts can act as nanoreactors that are of benefit for the antisintering of metals and resistance to coke formation in high-temperature reactions such as the CO2 reforming of methane. Notwithstanding the credible advances of core/yolk-shell catalysts, the enlarged shell diffusion effects that occur under high space velocity can deactivate the catalysts and hence pose a hurdle for the potential application of these types of catalysts. Here, we demonstrated the importance of the shell thickness and porosity of small-sized Ni@SiO2 nanoreactor catalysts, which can vary the diffusional paths/rates of the diffusants that directly affect the catalytic activity. The nanoreactor with an ∼4.5 nm shell thickness and rich pores performed the best in tolerating the shell diffusion effects, and importantly, no catalytic deactivation was observed. We further proposed a shell diffusion effect scheme by modifying the Weisz-Prater and blocker model and found that the "gas wall/hard blocker" formed on the openings of the shell pores can cause reversible/irreversible interruption of the shell mass transfer and thus temporarily/permanently deactivate the nanoreactor catalysts. This work highlights the shell diffusion effects, apart from the metal sintering and coke formation, as an important factor that are ascribed to the deactivation of a nanoreactor catalyst.

Knowledge of the electromagnetic microwave radiation–solid matter interaction and ensuing mechanisms at active catalytic sites will enable a deeper understanding of microwave-initiated chemical interactions and processes, and will lead to further optimization of this class of heterogeneous catalysis. Here, we study the fundamental mechanism of the interaction between microwave radiation and solid Fe catalysts and the deep dehydrogenation of a model hydrocarbon, hexadecane. We find that the size-dependent electronic transition of particulate Fe metal from a microwave “reflector” to a microwave “absorber” lies at the heart of efficient metal catalysis in these heterogeneous processes. In this regard, the optimal particle size of a Fe metal catalyst for highly effective microwave-initiated dehydrogenation reactions is approximately 80–120 nm, and the catalytic performance is strongly dependent on the ratio of the mean radius of Fe particles to the microwave skin depth (r/δ) at the operating frequency. Importantly, the particle size of selected Fe catalysts will ultimately affect the basic heating properties of the catalysts and decisively influence their catalytic performance under microwave initiation. In addition, we have found that when two or more materials─present as a mechanical mixture─are simultaneously exposed to microwave irradiation, each constituent material will respond to the microwaves independently. Thus, the interaction between the two materials has been found to have synergistic effects, subsequently contributing to heating and improving the overall catalytic performance.

The most important factors in improving the stability of nickel-based catalysts for methane reforming with carbon dioxide (so-called methane dry reforming, MDR) lie both in suppressing carbon formation and in inhibiting metal sintering at the high operating temperatures of this process (typically above 700 °C). Many efforts have been made to overcome these challenges, for example, by enhancing metal catalyst–support interactions. In this work, we used microwaves as an energy source to drive the MDR reactions under mild conditions with an overall measured catalyst bed temperature of below 220 °C. A high CH4 conversion of ca. 94% and a 97% conversion of CO2 were achieved over manganese-oxide modified ZrO2-supported nickel catalysts, exhibiting excellent anticoking properties. Compared with Ni/ZrO2 and Mn/ZrO2 catalysts, the Ni–Mn bimetal catalytic system stabilizes the catalytic activity of MDR by suppressing carbon deposition with the mixed-valent Mn3+/Mn2+ chemical states enhancing the absorption and conversion of CO2 during the reactions.

This work was supported by the Royal Society for international collaboration grants (IE160277 and IE/CNSFC170670) and Sir John Houghton Fellowship in Jesus College at University of Oxford. ZJ appreciated the institutional GCRF fund from EPSRC and JG appreciates the EUSTICE scholarship from University of Southampton. A series of visible-light-responsive BiOBrxI1-x solid solutions were prepared by a rapid and efficient ultrasonication synthesis and applied in photodegradation of Rhodamine B in aqueous solution. The detailed characterisations showed that the lattice parameters and their band structures of the BiOBrxI1-x solid solutions significantly deviated from the well-established Vegard’s law for solid solution materials. The Mulliken electronegativity and valence band XPS analyses revealed that the substitution of Br by less electronegative iodine can simultaneously modulate the edges of conductance and valence band of the BiOBr, leading to nonlinear dependence of bandgap (Eg) on the halogen anion concentrations. Although the solid solution displayed superior RhB photodegration activity to BiOI, only Br-rich BiOBrxI1-x solid solutions (x>0.5) were more active than BiOBr and BiOI, with the optimal one is BiOBr0.75I0.25. The Br-dependence of bandstructure and photocatalytic activity for the BiOBrxI1-x solid solutions as well as their rate-limiting radical species were also clarified based on experimental and theoretical analyses. Postprint

In present study, the in vitro and in vivo hemolysis inhibitory, protective effect against reactive oxygen species (ROS) induced oxidative damage in L02 cells, hypoglycemic, and antiglycation activities of DJP-2, a pure polysaccharide fraction from Diaphragma juglandis fructus, were investigated. Results demonstrated that DJP-2 showed remarkable hemolysis inhibitory activity. Pretreatment with DJP-2 markedly weakened the oxidative damage induced by H2O2 in hepatic L02 cells via strengthening the cell viability. DJP-2 also showed clear in vivo and in vitro hypoglycemic activities. Besides, DJP-2 with the concentration of 3 mg/mL exerted more significant antiglycation activities than aminoguanidine during 30 days of incubation. The results obtained in this study would be beneficial for the application of DJP-2 to treat various diseases related to oxidative stress and AGEs. The elucidation of the potential bioactivities of DJP-2 will facilitate its further study and application in the functional food industry and pharmaceuticals industry.

The importance of extracted and refined fossil carbonaceous fuels (petroleum, diesel etc.) to the development of human society cannot be overestimated. These natural resources have improved billions of lives, worldwide, in providing accessible, relatively inexpensive energy at nearly every scale. Notwithstanding the credible advances in renewable energy production over the past decade or so, the aerial combustion of coal, natural gas and liquid fossil fuels, given humankinds insatiable demand for power, will continue to be the ready source of more than 85% of the world's energy in the foreseeable and possibly the distant future. Human activities based on the combustion of fossil fuels, however, has led to significant anthropogenic emissions of carbon dioxide (CO2) to the atmosphere – and that fact is now seen as the major contributor to global warming and climate change. To stabilise global mean temperatures will depend on the ultimate transformation of humankind's energy system to one that does not introduce CO2 into the atmosphere. The hydrogen economy has long been mooted as a route to achieving the required net-zero emissions energy future. Paradoxically, fossil fuel sources such as petroleum, crude and extra-heavy crude oil, petrol, diesel and methane are reported here to produce high volumes of high-purity hydrogen through their microwave-initiated catalytic dehydrogenation using fine iron particles. The co-product of this dehydrogenation process, solid carbon, can be safely stored underground in perpetuity or converted in future to valuable hydrocarbons and other materials. Through their catalytic dehydrogenation to yield carbon-free hydrogen – rather than through their aerial combustion to produce carbon dioxide – petroleum and other fossil fuels can now serve as an energy pathway to stabilising global mean temperatures.

A new strategy is reported here to synthesize both nitrogen deficient and protonated graphitic carbon nitride (g-C3N4) nanosheets by the conjoint use of NH4Cl as a dynamic gas template together with hypophosphorous acid (H3PO2) as a doping agent. The NH4Cl treatment allows for the scalable production of protonated g-C3N4 nanosheets. With the corresponding co-addition of H3PO2, nitrogen vacancies, accompanied by both additional protons and interstitially-doped phosphorus, are introduced into the g-C3N4 framework, and the electronic bandgap of g-C3N4 nanosheets as well as their optical properties and hydrogen-production performance can be precisely tuned by careful adjustment of the H3PO2 treatment. This conjoint approach thereby results in improved visible-light absorption, enhanced charge-carrier separation and a high H2 evolution rate of 881.7 μmol h−1 achieved over the H3PO2 doped g-C3N4 nanosheets with a corresponding apparent quantum yield (AQY) of 40.4% (at 420 nm). We illustrate that the synergistic H3PO2 doping modifies the layered g-C3N4 materials by introducing nitrogen vacancies as well as protonating them, leading to significant photocatalytic H2 evolution enhancements, while the g-C3N4 materials doped with phosphoric acid (H3PO4) are simply protonated further, revealing the varied doping effects of phosphorus having different (but accessible) valence states., Nitrogen deficient and protonated g-C3N4 was fabricated by the conjoint protocol utilizing NH4Cl as gas template and H3PO2 as doping agent, leading to enhanced visible-light harvesting and charge carrier separation to achieve efficient H2 evolution.

The ubiquitous challenge of plastic waste has led to the modern descriptor plastisphere to represent the human-made plastic environment and ecosystem. Here we report a straightforward rapid method for the catalytic deconstruction of various plastic feedstocks into hydrogen and high-value carbons. We use microwaves together with abundant and inexpensive iron-based catalysts as microwave susceptors to initiate the catalytic deconstruction process. The one-step process typically takes 30–90 s to transform a sample of mechanically pulverized commercial plastic into hydrogen and (predominantly) multiwalled carbon nanotubes. A high hydrogen yield of 55.6 mmol g−1plastic is achieved, with over 97% of the theoretical mass of hydrogen being extracted from the deconstructed plastic. The approach is demonstrated on widely used, real-world plastic waste. This proof-of-concept advance highlights the potential of plastic waste itself as a valuable energy feedstock for the production of hydrogen and high-value carbon materials.

Funder: King Abdulaziz City for Science and Technology (KACST); doi: https://doi.org/10.13039/501100004919, With mounting concerns over climate change, the utilisation or conversion of carbon dioxide into sustainable, synthetic hydrocarbons fuels, most notably for transportation purposes, continues to attract worldwide interest. This is particularly true in the search for sustainable or renewable aviation fuels. These offer considerable potential since, instead of consuming fossil crude oil, the fuels are produced from carbon dioxide using sustainable renewable hydrogen and energy. We report here a synthetic protocol to the fixation of carbon dioxide by converting it directly into aviation jet fuel using novel, inexpensive iron-based catalysts. We prepare the Fe-Mn-K catalyst by the so-called Organic Combustion Method, and the catalyst shows a carbon dioxide conversion through hydrogenation to hydrocarbons in the aviation jet fuel range of 38.2%, with a yield of 17.2%, and a selectivity of 47.8%, and with an attendant low carbon monoxide (5.6%) and methane selectivity (10.4%). The conversion reaction also produces light olefins ethylene, propylene, and butenes, totalling a yield of 8.7%, which are important raw materials for the petrochemical industry and are presently also only obtained from fossil crude oil. As this carbon dioxide is extracted from air, and re-emitted from jet fuels when combusted in flight, the overall effect is a carbon-neutral fuel. This contrasts with jet fuels produced from hydrocarbon fossil sources where the combustion process unlocks the fossil carbon and places it into the atmosphere, in longevity, as aerial carbon - carbon dioxide.

The insatiable—and ever-growing—demand of both the developed and the developing countries for power continues to be met largely by the carbonaceous fuels comprising coal, and the hydrocarbons natural gas and liquid petroleum. We review the properties of the chemical elements, overlaid with trends in the periodic table, which can help explain the historical—and present—dominance of hydrocarbons as fuels for power generation. However, the continued use of hydrocarbons as fuel/power sources to meet our economic and social needs is now recognized as a major driver of dangerous global environmental changes, including climate change, acid deposition, urban smog and the release of many toxic materials. This has resulted in an unprecedented interest in and focus on alternative, renewable or sustainable energy sources. A major area of interest to emerge is in hydrogen energy as a sustainable vector for our future energy needs. In that vision, the issue of hydrogen storage is now a key challenge in support of hydrogen-fuelled transportation using fuel cells. The chemistry of hydrogen is itself beautifully diverse through a variety of different types of chemical interactions and bonds forming compounds with most other elements in the periodic table. In terms of their hydrogen storage and production properties, we outline various relationships among hydride compounds and materials of the chemical elements to provide some qualitative and quantitative insights. These encompass thermodynamic and polarizing strength properties to provide such background information. We provide an overview of the fundamental nature of hydrides particularly in relation to the key operating parameters of hydrogen gravimetric storage density and the desorption/operating temperature at which the requisite amount of hydrogen is released for use in the fuel cell. While we await the global transition to a completely renewable and sustainable future, it is also necessary to seek CO 2 mitigation technologies applied to the use of fossil fuels. We review recent advances in the strategy of using hydrocarbon fossil fuels themselves as compounds for the high capacity storage and production of hydrogen without any CO 2 emissions. Based on these advances, the world may end up with a hydrogen economy completely different from the one it had expected to develop; remarkably, with ‘Green hydrogen' being derived directly from the hydrogen-stripping of fossil fuels. This article is part of the theme issue ‘Mendeleev and the periodic table'.

The demarcation of the chemical elements into metals and non-metals dates back to the dawn of Dmitri Mendeleev's construction of the periodic table; it still represents the cornerstone of our view of modern chemistry. In this contribution, a particular emphasis will be attached to the question ‘Why do the chemical elements of the periodic table exist either as metals or non-metals under ambient conditions?’ This is perhaps most apparent in the p-block of the periodic table where one sees an almost-diagonal line separating metals and non-metals. The first searching, quantum-mechanical considerations of this question were put forward by Hund in 1934. Interestingly, the very first discussion of the problem—in fact, a pre-quantum-mechanical approach—was made earlier, by Goldhammer in 1913 and Herzfeld in 1927. Their simple rationalization, in terms of atomic properties which confer metallic or non-metallic status to elements across the periodic table, leads to what is commonly called the Goldhammer–Herzfeld criterion for metallization. For a variety of undoubtedly complex reasons, the Goldhammer–Herzfeld theory lay dormant for close to half a century. However, since that time the criterion has been repeatedly applied, with great success, to many systems and materials exhibiting non-metal to metal transitions in order to predict, and understand, the precise conditions for metallization. Here, we review the application of Goldhammer–Herzfeld theory to the question of the metallic versus non-metallic status of chemical elements within the periodic system. A link between that theory and the work of Sir Nevill Mott on the metal-non-metal transition is also highlighted. The application of the ‘simple’, but highly effective Goldhammer–Herzfeld and Mott criteria, reveal when a chemical element of the periodic table will behave as a metal, and when it will behave as a non-metal. The success of these different, but converging approaches, lends weight to the idea of a simple, universal criterion for rationalizing the instantly-recognizable structure of the periodic table where … the metals are here, the non-metals are there … The challenge of the metallic and non-metallic states of oxides is also briefly introduced. This article is part of the theme issue ‘Mendeleev and the periodic table’.

Coal tar, a major by-product of the coal industry, presents considerable difficulties in its refining and conversion into fuels due to its complex chemical composition and physical properties, such as high viscosity, corrosiveness, thermal instability, etc. Here we report a new route for producing hydrogen-rich gases together with carbonaceous materials, including carbon nanotubes, through the microwave-initiated catalytic deep dehydrogenation of coal tar using inexpensive iron catalysts. The resulting carbonaceous materials generated over the catalyst were investigated using a variety of techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), temperature programmed oxidation (TPO) and Raman spectroscopy. Importantly, we have found that an aqueous emulsion feed of the coal tar enables considerably easier handling and an enhanced hydrogen production whilst also significantly reducing the extent of catalyst deactivation. This behaviour is shown to be assisted by the phenomenon of micro-explosion that enhances mass and heat transfer during the catalytic reactions.

A new strategy is reported here to synthesize both nitrogen deficient and protonated graphitic carbon nitride (g-C3N4) nanosheets by the conjoint use of NH4Cl as a dynamic gas template together with hypophosphorous acid (H3PO2) as a doping agent. The NH4Cl treatment allows for the scalable production of protonated g-C3N4 nanosheets. With the corresponding co-addition of H3PO2, nitrogen vacancies, accompanied by both additional protons and interstitially-doped phosphorus, are introduced into the g-C3N4 framework, and the electronic bandgap of g-C3N4 nanosheets as well as their optical properties and hydrogen-production performance can be precisely tuned by careful adjustment of the H3PO2 treatment. This conjoint approach thereby results in improved visible-light absorption, enhanced charge-carrier separation and a high H2 evolution rate of 881.7 μmol h−1 achieved over the H3PO2 doped g-C3N4 nanosheets with a corresponding apparent quantum yield (AQY) of 40.4% (at 420 nm). We illustrate that the synergistic H3PO2 doping modifies the layered g-C3N4 materials by introducing nitrogen vacancies as well as protonating them, leading to significant photocatalytic H2 evolution enhancements, while the g-C3N4 materials doped with phosphoric acid (H3PO4) are simply protonated further, revealing the varied doping effects of phosphorus having different (but accessible) valence states.

The petroleum refining process begins with distillation, first at atmospheric pressure and after at reduced pressure. The volatile fractions, in both cases, have greater economic value, and the distillation residue-produced atmospheric residue and vacuum residue represent a significant portion of a barrel of crude. The need to convert bottom of the barrel into cleaner and more valuable olefins and liquid products is continuously increasing. Thus, residue must be converted into more valuable products, and further processes can be employed for upgrading residue. Examples are delayed coking, visco-reduction, and fluidized catalytic cracking. On the other hand, the optimization of refining facilities to deal with such feeds brings economic competitiveness since these oils have low prices in the international market. Studies on processes and catalytic cracking are quite important under this aspect. The conversion of heavy petroleum fraction into valuable liquid products and high value chemicals has been important objectives for upgrading heavy petroleum oils.

Iron oxide nanostructured catalysts have emerged as potential candidates for efficient energy conversion and electrochemical energy storage devices. However, synthesis and design of nanomaterial plays a key role in its performance and efficiency. Herein, we describe a one-pot solution combustion synthesis (SCS) of α-Fe2O3 with glycine as a fuel, and a subsequent reduction step to produce iron-containing catalysts (i.e., Fe3O4, Fe–Fe3O4, and Fe0). The synthesized iron-based nanoparticles were investigated for methyl orange (MO) degradation through Microwave (MW) energy under continuous flow conditions. Fe–Fe3O4 showed higher MO degradation efficiency than α-Fe2O3, Fe3O4 and Fe0 at low absorbed MW power (i.e. 5–80 W). The enhanced degradation efficiency is associated to the combination of higher availability of electron density and higher heating effect under MW energy. Investigation of dielectric properties showed relative dielectric loss of Fe3O4, Fe–Fe3O4, and Fe0 as 3847, 2010, and 1952, respectively. The calculated average local temperature by the comparative analysis of MW treatment with conventional thermal (CT) treatment showed a marked thermal effect of MW-initiated MO degradation. This work highlights the potential of microwave-driven water depollution under continuous-flow processing conditions and demonstrates the positive impact that earth-abundant Fe catalyst synthesized by green SCS method can have over the treatment of wastewater.

With increasing concerns about climate change caused by carbon dioxide emissions, decarbonization is rapidly becoming an important and attractive challenge for continuing fossil fuel utilization. This paper reports an entirely new route of producing hydrogen directly from crude oil through microwave-initiated, iron-catalyzed deep dehydrogenation. Importantly, there is very little carbon dioxide emission in this process, a key element towards stabilising global mean temperature. The analytical techniques of Scanning Electron Microscope, Transmission Electron Microscopy, Temperature Programmed Oxidation and Raman spectroscopy were employed to interrogate the catalytic process and the nature of carbon deposition over the catalyst which was brought about by the dehydrogenation process. The presence of emulsified feed significantly promotes hydrogen production, owing to its presence depressing carbonaceous deposition on the catalyst together with the occurrence of the micro-explosion phenomenon.

Ordered mesoporous SiC materials with different architectures were facilely prepared by a nanocasting method using SBA-15, KIT-6 and MCM-41 as hard templates, and the latter obtained nickel-containing SiC materials were applied to the dry reforming of methane. After reacting at 750 °C for 25 h, the catalytic activity and stability are declined in the sequence of Ni/SiC-KIT–6 > Ni/SiC-SBA–15 >> Ni/SiC-MCM-41. Physicochemical properties of prepared mesoporous Ni/SiC catalysts were further characterized by using N2 adsorption, inductively coupled plasma atomic emission spectrometer (ICP-AES), X-ray diffraction (XRD), H2 chemisorption, temperature programmed reduction (TPR), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) etc. The characterization results showed that both Ni/SiC-KIT-6 and Ni/SiC-SBA-15 inherit the ordered mesoporous structure from their mother templates, while Ni/SiC-MCM-41 had a poor mesoporous structure since the pore size of MCM-41 is too narrow to penetrate precursors. Ni/SiC-KIT-6 showed strong confinement effect of three-dimensional bicontinuous mesoporous structure, leading to the well dispersion/anchoring of metal particle inside the pores and strong metal support interaction. Meanwhile, Ni/SiC-SBA-15 showed a confinement effect of two-dimensional channel arrays but with a few large Ni particles outside the mesopores, which may result in the carbon deposition and catalytic deactivation. And due to the rigid confinement effect and the superior structure stability at high temperatures, Ni/SiC-KIT-6 showed the excellent catalytic activity and stability for dry reforming of methane.

Microwave - assisted catalysis has previously been shown to offer unique advantages in the rapid production of hydrogen from hydrocarbons fuels. In this work, we have prepared a series of supported catalysts with varying iron content and support materials, and evaluated the resulting H2 production from hexadecane, a key representative component of diesel fuel. These catalysts, under microwave activation, exhibit high selectivity for H2 over hydrocarbons in the effluent gas. Microwave-assisted Fe catalysts supported on SiC at low Fe loading levels (

Six polysaccharide fractions (DOP30, DOP40, DOP50, DOP60, DOP70, and DOP80) were purified successfully from Dendrobium officinale by the ethanol precipitation method, and their physicochemical characterizations and antioxidant properties were investigated by the chemical methods, high performance liquid chromatography (HPLC), UV–vis (UV) and Fourier transform infrared spectroscopy, and 1,1-diphenyl-2-picrylhydrazyl radical scavenging ability, 2,2-azinobis-6-s (3-ethylbenzothiazoline sulfonic acid) (ABTS) radical scavenging activity, hydroxyl radical scavenging activity, and reducing power, respectively. Results estimated their weight-average molecular weight (Mw) to be 361.4, 242.6, 192.3, 100.5, 23.7, and 8.2 kDa, respectively. Mannose and glucose were the major monosaccharide components presenting in the polysaccharide fractions. However, monosaccharide compositions were significantly different among the DOPs, namely, DOPs with a smaller Mw contained more species of monosaccharides. All six polysaccharide fractions displayed antioxidant activities in vitro according to the antioxidant tests, and a small molecular weight of polysaccharides (DOP80 and DOP70) showed stronger antioxidant activities. The present results suggest that DOPs could potentially be used as a natural antioxidant, especially the small molecular weight ones.

A water-soluble polysaccharide fraction (DJP-2) isolated from Diaphragma juglandis was successfully purified by ion-exchange chromatography (DEAE-cellulose) and gel-permeation chromatography (Sephadex G-100). The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of DJP-2 were 4.95 and 3.99kDa, respectively. Monosaccharide component analysis indicated that DJP-2 comprised arabinose, galactose, glucose, xylose, and mannose in a molar ratio of 0.27:0.55:1:0.14:0.08. The evaluation of the antioxidant and antibacterial activities of polysaccharides from Diaphragma juglandis fructus indicated that they could be explored as promising natural antioxidant and bacteriostatic agents in the food and pharmaceutical industries.

Dendrobium officinale has been used in China for several thousand years as a health food and has become one of the most expensive tea materials worldwide as a result of extremely scarce resources in the wild and an increasing demand. Hence, it is very important to improve the depth and width of its application. In the present study, the physico-chemical, surface chemistry and thermal properties of micron range particles and coarse particles prepared by superfine grinding and shear pulverization were investigated.; Results: As the particle size decreased, the specific surface area of D. officinale powders increased significantly. Microscopy observations confirmed that superfine grinding effectively changed the original structure of D. officinale. The Fourier transform infrared spectroscopy spectra depicted the characteristic bands shifted in terms of absorbance and/or wave number as the powder particle size decreased. The crystallinity and intensity of the crystal peaks of D. officinale powders increased as the particle size decreased. Moisture sorption isotherms suggested that superfine powders were more unstable as a result of the increase in surface area, as well as the exposure of polar groups.; Conclusion: The results of the present study suggest that superfine grinding may provide new methods of processing for D. officinale with respect to further enhancement of its application value. © 2017 Society of Chemical Industry.; © 2017 Society of Chemical Industry.

Coking leads to the deactivation of solid acid catalyst. This phenomenon is a ubiquitous problem in the modern petrochemical and energy transformation industries. Here, we show a method based on microwave cavity perturbation analysis for an effective examination of both the amount and the chemical composition of cokes formed over acid zeolite catalysts. The employed microwave cavity can rapidly and non-intrusively measure the catalytically coked zeolites with sample full body penetration. The overall coke amount is reflected by the obtained dielectric loss (ε″) value, where different coke compositions lead to dramatically different absorption efficiencies (ε″/cokes’ wt%). The deeper-dehydrogenated coke compounds (e.g., polyaromatics) lead to an apparently higher ε″/wt% value thus can be effectively separated from lightly coked compounds. The measurement is based on the nature of coke formation during catalytic reactions, from saturated status (e.g., aliphatic) to graphitized status (e.g., polyaromatics), with more delocalized electrons obtained for enhanced Maxwell–Wagner polarization., Catalyst deactivation by coke deposition is a major drawback in industrial processes. Here, the authors show a non-intrusive microwave cavity perturbation technique as a powerful tool to determine the nature and extent of coke accumulation in industrially-relevant zeolite catalysts.

The inhibitory effect of maca extractant, lycopene, and their combination was evaluated in benign prostatic hyperplasia (BPH) mice induced by testosterone propionate. Mice were divided into a saline group, solvent control group and testosterone propionate-induced BPH mice [BPH model group, solvent BPH model group, benzyl glucosinolate group (1.44 mg/kg), maca group (60 mg/kg), lycopene treated (15, 5, and 2.5 mg/kg), maca (30 mg/kg) combine lycopene treated (7.5, 2.5, and 1.25 mg/kg), and finasteride treated]. Benzyl glucosinolate was used in order to evaluate its pharmacological activity on BPH to find out whether it is the major active component of maca aqueous extract. Finasteride was used as positive control. The compounds were administered once for 30 successive days. Compared with solvent BPH model group, BPH mice fed with maca (30 mg/kg) and lycopene (7.5 mg/kg) combination exhibited significant reductions in the prostatic index, prostatic acid phospatase, estradiol, testosterone, and dihydrotestosterone levels in serum. They also had similar histological compared with those aspects observed in the mice in the solvent control group. The results indicated that combination of maca and lycopene synergistically inhibits BPH in mice. Copyright © 2017 John Wiley & Sons, Ltd.

The thermodynamics of jet fuel range alkane synthesis from carbon dioxide and hydrogen has been investigated. The hydrocarbon synthesis process is divided into three elementary steps, including light olefins formation (C2-C6) from hydrogenation of CO2, α-olefins (C7-C16) synthesis from oligomerization of light olefins, and hydrogenation of α-olefins (C8-C16) to straight-chain paraffin (C8-C16). The enthalpy changes and Gibbs free energy changes of the relevant reactions were calculated, and the equilibrium products distribution was computed based on the Gibbs free energy minimization method. The calculation results show that lower temperature (below 673.15 K), higher pressure (3 MPa), higher molar ratio of H2 to CO2 (3:1-4:1), and introducing a small amount of N2 in the reactants are favorable for the hydrogenation of CO2; lower temperature (below 500 K), higher pressure (2-3 MPa), addition of N2 is favorable for the oligomerization of light olefins; and lower temperature (below 700 K), higher pressure (2-3 MPa), and addition of N2 is favorable for the hydrogenation of α-olefins. The overall positive effect of introducing N2 results from its heat dilution of the process. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.

Hydrogen as an energy carrier promises a sustainable energy revolution. However, one of the greatest challenges for any future hydrogen economy is the necessity for large scale hydrogen production not involving concurrent CO2 production. The high intrinsic hydrogen content of liquid-range alkane hydrocarbons (including diesel) offers a potential route to CO2 -free hydrogen production through their catalytic deep dehydrogenation. We report here a means of rapidly liberating high-purity hydrogen by microwave-promoted catalytic dehydrogenation of liquid alkanes using Fe and Ni particles supported on silicon carbide. A H2 production selectivity from all evolved gases of some 98 %, is achieved with less than a fraction of a percent of adventitious CO and CO2 . The major co-product is solid, elemental carbon.

In the 21st century, obesity has become a serious problem because of increasing obese patients and numerous metabolic complications. The primary reasons for this situation are environmental and genetic factors. In 2007, FTO (fat mass and obesity associated) was the first gene identified through a genome-wide association study (GWAS) associated with obesity in humans. Subsequently, a cluster of single nucleotide polymorphisms (SNPs) in the first intron of the FTO gene was discovered to be associated with BMI and body composition. Various studies have explored the mechanistic basis behind this association. Thus, emerging evidence showed that FTO plays a key role regulating adipose tissue development and functions in body size and composition. Recent prevalent research topic concentrated in the three neighboring genes of FTO: RPGRIP1L, IRX3 and IRX5, as having a functional link between obesity-associated common variants within FTO and the observed human phenotypes. The purpose of this review is to present a comprehensive picture of the impact of FTO on obesity susceptibility and to illuminate these new studies of FTO function in adipose tissue.

In herbal markets, an overwhelming majority the D. officinale are sold in spiral or spring form, and this kind of product would lead to the incomplete release of some nutrients. To increase the bioaccessibility of D. officinale, we report a method of pulverisation treatments including general and superfine grinding to reduce the particle size. In comparison with coarse D. officinale, the superfine ground D. officinale with particle sizes of

Thermodynamic calculations and analysis were carried out for a rational understanding of the results from selected laboratory MTH reactions. Simulations without solid carbons (coke), CO, CO2 and light alkanes target on the yield of olefin and aromatic products, which has been found better referenced to the real experimental observations that occur in time-on-stream (TOS). The confliction between simulated data and real experimental results is presumably ascribed to the limited dwelling time of products in the reaction system. Hydrocarbon pool based reactions donate olefins and methyl-benzenes as primary products in a continuous-flow MTH reaction; when the dwelling time of product extends intra-conversions (H2 transfers) between products would further adjust the composition of MTH yield, in which case alkanes and aromatic products (cokes precursors) increase. In the case of intra-conversions are ignored due to limited product dwelling time, thermodynamic calculation on Gibbs free energy change of selected sub reactions shows fairly close results to the real experimental data, which well supports the above explanations. This work highlights the importance of proper choosing target products and/or sub reactions for a rational thermodynamic prediction of MTH product distribution obtained in time-on-stream.

The QDB-5 sulfur tolerant CO shift catalyst, with anti-methanation property by supported compositing alkali promoters, has been proved to effectively reduce the outlet methane content in the condition of a low water gas ratio. Thus, a new technology based on a lower water/gas ratio than before has been developed with the new catalyst. The CO conversion at lower temperatures and catalyst stability were confirmed by long term industrial application. The high temperature catalyst performance also showed a better result than the conventional commercial catalyst, with higher CO conversion and well controlled methane outlet. Our research and the industrial application of catalyst have shown the importance of alkali metals as core promoters for such kind of catalysts.

Using hydrogen generated in situ from aqueous phase reforming provides an efficient and economic route for glycerol hydrogenolysis. A Pt-Ni bimetallic catalyst supported on γ-Al 2 O 3 has been prepared to catalyze the selective hydrogenolysis of glycerol to 1,2-propanediol, with glycerol conversion reaching 71.4% in 3 h. The significant promotion of conversion and selectivity could be explained by the formation of Pt-Ni alloy based on catalyst characterization. The effects of Pt/Ni ratio, reaction temperature and reaction time on the conversion of glycerol as well as product selectivity were also investigated.

A series of Sc-doped ZrO2 supports, with Sc2O3 content in the range of 0 to 7.5% (mol/mol), were prepared using the hydrothermal method. Ni/Sc-doped ZrO2 catalysts with nickel loading of 10% (w/w) were prepared using impregnation method, and characterized with the use of XRD, Raman, H2 temperature-programmed reduction (H2-TPR), H2 temperature-programmed desorption (H2-TPD), XPS, and in situ FT-IR techniques. The catalytic performances of Ni/Sc-doped ZrO2 catalysts in maleic anhydride hydrogenation were tested. The results showed that the introduction of Sc3+ into ZrO2 support could effectively manipulate the distribution of maleic anhydride hydrogenation products. &gamma, butyrolactone was the major hydrogenation product over Sc-free Ni/ZrO2 catalyst with selectivity as high as 65.8% at 210 &deg, C and 5 MPa of H2 pressure. The Ni/Sc-doped ZrO2 catalyst, with 7.5 mol% of Sc2O3 content, selectively catalyzed maleic anhydride hydrogenation to succinic anhydride, the selectivity towards succinic anhydride was up to 97.6% under the same reaction condition. The results of the catalysts&rsquo, structure&ndash, activity relationships revealed that there was an interdependence between the surface structure of ZrO2-based support and the C=O hydrogenation performance of the ZrO2-based supported nickel catalysts. By controlling the Sc2O3 content, the surface structure of ZrO2-based support could be regulated effectively. The different surface structure of ZrO2-based supports, resulted in the different degree of interaction between the nickel species and ZrO2-based supports, furthermore, the different interaction led to the different surface oxygen vacancies electron properties of ZrO2-based supported nickel catalysts and the C=O hydrogenation activity of the catalyst. This result provides new insight into the effect of ZrO2 support on the selective hydrogenation activity of ZrO2-supported metal catalysts and contributes to the design of selective hydrogenation catalysts for other unsaturated carbonyl compounds.

Global methane emission from coal mines were estimated to be approximately 584 MMTCO2 E in 2010, which is a huge waste of energy resources and is an important source of greenhouse gas (GHG) emission. Coal mine methane (CMM) whose methane content is 30∼60% with the rest of air is difficult to use directly. A novel process for CMM utilization is developed in this work. CMM is used as the feedstock for urea synthesis. This process does not require separation or further purification of CMM, but converts the methane into hydrogen through the oxygen in it and by adding steam. The reformate can be further processed into a mixture of hydrogen and nitrogen with a molar ratio of H2:N2 = 3:1, which can then be used for urea synthesis. This process has been analyzed by Aspen Plus. It is found that the optimal CMM composition for urea production is 42% of methane in the air system, with water added at an H2O/CH4 ratio of 3.26. Reforming catalyst has been developed and tested in a simulated industrial reactor, with CMM simulated by mixing civil use grade methane and air. The reformate composition was analyzed by gas chromatography (GC) and the results match the simulation very well. A 10-day test showed high stability of the catalyst. In addition, the reforming catalyst after 10 days of operation was characterized using XRD and Laser Raman. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd.

Hydrogen is a clean energy carrier, but does not occur naturally. Here we reported a novel process to get instant hydrogen from a mixture of methanol and dilute hydrogen peroxide. The hydrogen can be obtained instantly once the fuel mixture is in contact with the platinum catalyst without any external heating or any energy input. The catalyst can be started and stopped more than 100 times before a new load of catalyst is required. Pure hydrogen is produced by combining the reforming catalyst with a water gas shift catalyst bed, which is driven by heat from the reforming process. Interestingly we discovered that only platinum catalysts can synergistically activate methanol and hydrogen peroxide to give hydrogen spontaneously. The preparation conditions and impurities have significant effects on the reforming process. This work overcomes the various hurdles of on-board reforming for hydrogen production and provides a way to catalyse the utilization of fuel cells.

Methanol-to-hydrocarbon (MTH) process over acidic zeolite catalysts has been widely utilised to yield many types of hydrocarbons, some of which are eventually converted into the highly dehydrogenated (graphitized) carbonaceous species (cokes). The coking process can be divided into two parallel pathways based on the accepted hydrocarbon pool theory. From extensive investigations, it is reasonable to conclude that inner zeollite cavity/channel reactions at acidic sites generate cokes. However, coke formation and accumulation over the zeolite external surfaces play a major role in reaction deactivation as they contribute a great portion to the total coke amount. Herein we have reviewed previous literatures and included some recent works from KOPRC in understanding the nature and mechanism of coke formation, particularly during an H-ZSM-5 catalysed MTH reaction. We specially conclude that rapid aromatics formation at the zeolite crystalite edges is the main reason for later stage coke accumulation on the zeolite external surfaces. Accordingly, the catalyst deactivation is in a great certain to arise at those edge areas due to having the earliest contact with the incoming methanol reactant. The final coke structure is therefore built up with layers of poly-aromatics, as the potential sp2 carbons leading to pre-graphite structure. We have proposed a coke formation model particularly for the acidic catalyst, which we believe will be of assistance in understanding—and hence minimising—the coke formation mechanisms.