FTIR Of CO Research Articles

Oxidation behaviors of Hongqian heavy crude oil characterized by TG-DSC-FTIR-MS within full temperature regions

To better understand in-situ combustion (ISC) theory and reveal the oxidation behavior and mechanism of Hongqian (HQ) heavy crude oil, the thermo-oxidative characteristics and kinetics of HQ heavy oil were studied under air conditions using TG-DSC-FTIR-MS technique. According to the TG/DTG-DSC curves, the oxidation reactions of HQ heavy oil can be divided into low temperature oxidation (LTO), fuel deposition (FD) and high temperature combustion (HTC) stages. The reaction mechanism for each reaction interval was comprehensively analyzed by online FTIR and MS analysis. In FTIR spectra, H2O, hydrocarbon, CO2, CO, –COOH, and aromatic ring were observed during the oxidation process, which are used to explain the occurrence of the possible decomposition/isomerization of hydroperoxides in the later stage of LTO and the important role of light hydrocarbons evaporation, thermal oxidative cracking and polycondensation for coke formation at FD stage, coke combustion at HTC stage, as well as the possible hysteresis of dehydrogenation and aromatization at FD and HTC stages. The strong variation of activation energy with conversion degree confirms the complex oxidation reactions. MS analysis of H2, CH4, H2O, CO, O2, and CO2 produced during oxidation process helps to verify these reaction mechanisms; and provide more information about the in-situ H2 generation and the conditions where H2 generation may occur as well as the generation of CO and its possible reaction mechanism in LTO reactions. These obtained data aid in a deeper insight into crude oil oxidation mechanism and provide reference for establishing accurate reaction scheme and reaction kinetic model for the precise simulation of ISC processes.

Silica sol gel assisted defect patching of SSZ-13 zeolite membranes for CO2/CH4 separation

• Silica sol post-treatment effectively patched defects of SSZ-13 zeolite membrane. • Ethanol content of silica sol is a significant parameter in defect patching process. • More than 6-fold increase in selectivity is achieved for CO 2 /CH 4 mixed gas test. • The modified SSZ-13 membrane has superior performance in Robeson plot of CO 2 /CH 4. Intercrystalline defects are commonly present in zeolite membranes formed during membrane synthesis and calcination process. Therefore, the selection of a suitable post-treatment method is of particular importance. In this work, SSZ-13 membrane defects were significantly reduced by dipping in the different ethanol/TEOS molar ratios of the silica sol solutions. Characterizations including FTIR, FESEM, EDX, BET, and gas adsorption isotherms of CO 2 and CH 4 revealed that silanes groups were properly placed on the surface of the zeolite while the crystal structure and zeolitic pores remained intact. Permporometry analysis was also carried out to find the effectiveness of the applied patching method. Permeation of CO 2 and CH 4 and CO 2 /CH 4 ideal and mixture selectivity through the fresh and improved membranes was investigated. The results showed that ethanol/TEOS molar ratio of 95.5 increased the single gas selectivity from 33 to 176 at 30 °C and the pressure difference of 100 kPa, while the permeation of CO 2 declined by 15%. In the mixed gas conditions, the selectivity of CO 2 /CH 4 reached a really high value of 660, proving that this post-treatment modification is very effective in SSZ-13 zeolite membrane.

Influence of ionic conductivity and dielectric constant of the catalyst on DBD plasma-assisted CO2 hydrogenation into methanol

Dielectric barrier discharge (DBD) plasma technology is a promising method for producing methanol from CO2 hydrogenation as the reaction can be run at atmospheric pressure and temperatures below 100 °C. The choice of the catalyst is crucial and has to be made not only according to its activity and selectivity towards the desired product, but its effect on plasma properties. In this work, the influence of several important catalytic properties of DBD plasma such as the dielectric constant of the catalyst and ionic conductivity is studied. The effects of the catalyst support and the addition of promoters on CO2 hydrogenation under DBD plasma are also studied. To this end, Cu and Cu–ZnO catalysts supported on γ-Al2O3 and a template-free seedless ZSM-5 (Si/Al molar ratio of 23) were prepared to study their catalytic performance on CO2 hydrogenation into methanol under DBD plasma. These catalysts were fully characterized by XRD, SEM, N2 physisorption, temperature programmed reduction and in situ FTIR CO adsorption. The relative complex permittivity of the catalysts was measured and the ionic conductivity was estimated using a modified Debye model. In this paper, the role of the ionic conductivity of the catalyst was identified as a crucial parameter in plasma-assisted CO2 hydrogenation. It was found that the lower the value of the ionic conductivity, the better the CO2 conversion. Indeed, high ionic conductivity reduces the density of the plasma and decreases the dissociation of CO2. The highest CO2 conversion value (34.0%) was observed for the nonconductive alumina support, whereas the highest methanol yield (0.5%) was observed for the zeolite-supported Cu–ZnO catalyst.

Effects of rhodium catalyst support and particle size on dry reforming of methane at moderate temperatures

• Dry reforming of methane at 400–600 °C over supported Rh catalysts was studied. • Catalyst activity depended on Rh particle size, support type, and acidic properties. • Specific activity increased with decreasing Rh particle size. • Rh/SiO 2 -TiO 2 performed the best, giving H 2 and CO yields of 1.8% and 4.2% at 400 °C. • Electron-deficient Rh δ+ species may improve the specific activity of the catalysts. Dry reforming of methane at 400–600°C was studied over Rh catalysts with different supports (SiO 2 , γ-Al 2 O 3 , α-Al 2 O 3 , TiO 2 , ZrO 2 , CeO 2 , Y 2 O 3 , SiO 2 -Al 2 O 3 , SiO 2 -MgO, SiO 2 -TiO 2 ), Rh particle sizes (1.5–15.6 nm), and acidic properties (acidic site density, 0.37–3.40 mmol g −1 ). Catalysts with a high density of strongly acidic sites (e.g., α-Al 2 O 3 , SiO 2 -MgO) showed low activity and gradually deactivated with time on stream; in contrast, catalysts with a low density of strongly acidic sites (e.g., TiO 2 , γ-Al 2 O 3 ) showed high, stable activity. Rh/SiO 2 -TiO 2 showed the best performance, with H 2 and CO yields of 1.8% and 4.2% at 400°C and yields 37.3% and 53.1% at 600°C, respectively. Catalyst activity depended strongly on Rh particle size; specific activity increased with decreasing particle size, indicating that Rh-catalyzed dry reforming of methane is structure-sensitive. The support type influenced not only the dispersion and reducibility of the Rh particles but also the specific activity of the catalysts. CO temperature-programmed desorption and FT-IR suggested that electron-deficient Rh δ+ species were generated by electronic interactions between the Rh particles and the support, and the number of these species strongly influenced the overall catalytic activity.

Kinetics of liquid-phase diphenylacetylene hydrogenation on “single-atom alloy” Pd-Ag catalyst: Experimental study and kinetic analysis

• Pd 1 Ag 3 SAA catalyst demonstrates extremely high selectivity in diphenylethene (ca. 98 %). • Selectivity of Pd 1 Ag 3 does not depend on P(H 2 ) and DPA concentration. • Proposed kinetic model is capable to describe the experimental dependencies. Catalytic performance of Pd 1 Ag 3 /Al 2 O 3 single-atom alloy (SAA) catalyst was studied in liquid-phase hydrogenation of diphenylacetylene (DPA) and compared with the performance of the reference monometallic Pd/Al 2 O 3 . Formation of SAA structure in Pd 1 Ag 3 /Al 2 O 3 was confirmed by FTIR CO technique. It was found that Pd 1 Ag 3 /Al 2 O 3 single-atom alloy catalyst exhibits excellent selectivity in diphenylethene (stilbene) (ca. 98 %), which remains constant over a wide range of DPA conversions (0–95%), while over Pd/Al 2 O 3 selectivity decreases steadily with the increase in DPA conversion. It is remarkable that the selectivity of Pd 1 Ag 3 /Al 2 O 3 depends neither on hydrogen pressure (5–15 bar), nor on DPA concentration (0.0262 – 0.159 mol/l). In contrast, over the reference Pd/Al 2 O 3 selectivity tends to decrease with increasing P(H 2 ) and decreasing DPA concentration. The proposed reaction network comprises hydrogenation of DPA in a parallel formation of cis and trans -stilbene with following hydrogenation to bibenzyl and direct formation of the latter from the initial DPA. The calculations clearly shows the capability of the kinetic model to describe the experimental dependencies for Pd 1 Ag 3 single-atom catalyst in an excellent way with the degree of explanation equal to ca. 99 %.

CuPd bimetallic catalyst with high Cu/Pd ratio and its application in CO2 hydrogenation

The surface and catalytic properties Cu-Pd bimetallic catalyst with a high Cu/Pd ratio of 33.5 was investigated for the hydrogenation of CO2 and was compared with the corresponding monometallic catalysts. The catalysts were synthesized by the incipient-wetness impregnation method, characterized by N2-physisorption, XRD, TPR, CO pulse titration, N2O chemisorption, CO2-TPD, and FT-IR of adsorbed CO, and were evaluated in a fixed-bed reactor. The interaction between Cu and Pd results in a better dispersion of both Cu and Pd atoms and facilitates the reduction properties. Phase separation of Pd1Cu3 alloy and Cu appears over the bimetallic catalyst, while at some part of the catalysts, isolated Pd sites exist over the Cu-rich particles. Both geometric and electronic effects are present over the bimetallic catalyst. The catalytic performances are found to be similar over Cu/SiO2 and Cu-Pd/SiO2 when normalized to the surface Cu sites. Specifically, CuPd/SiO2 shows enhanced activity than Cu/SiO2 mainly due to the geometric effect, whereas the electronic effect is weak for the catalytic performance.

Boron alumina: qualitative investigation of the surface acidity by FTIR measurements of CO adsorption

The aim of this work was to determine the nature and the strength of surface acid sites present on boron alumina surface. From the results obtained by FTIR of CO adsorbed at −135 °C, it can be concluded that the boron alumina has a Brönsted acidity due to the OH groups. These Brönsted acid sites are stronger than those of γ-alumina but in much smaller quantities due to its lower specific surface area. Similarly, it is noted that the boron alumina exhibits a single OH type with a single band around 3701 cm−1. This band represents a single configuration of OH species linked to boron and this species is disturbed by the adsorption of the CO probe molecule whereas on alumina we notice the presence of four OH species linked to aluminum. Only one of which is disturbed by the adsorption of CO with a decrease in the intensity of this band and the increase in the intensity of a band present at lower frequency.

Identifying the Active Silver Species in Carbonylation of Dimethyl Ether over Ag−HMOR

AbstractAs one of the key steps in ethanol production from syngas, dimethyl ether (DME) carbonylation to methyl acetate (MA) catalyzed by zeolite has drawn much attention. H‐mordenite (HMOR) modified with metal has been continuously developed for improving catalytic performance. Here, we investigated the role of Ag species through three series of Ag−HMOR catalysts prepared through altering Ag loading, varying reduction temperature and additional ion exchange. TEM, XPS, CO FTIR and UV‐Vis spectroscopy were employed to identify the nature and the amount of Ag species in xAg−HM with different Ag loading. Taken together with catalytic performance evaluation, 5Ag−HM with the moderate size of Ag0 species (Agnδ+ and Agm clusters) was proved to have greatest promotion effect on DME carbonylation. This was also evidenced by further improved MA formation rate over catalysts via elevating reduction temperature or via additional NH4Cl ion exchange, which contained more Ag0 and fewer Ag+ species respectively. These provide insight into metal‐modified HMOR, inspiring design and fabrication of zeolite catalysts with multi‐active sites.

Support morphology effect on the selective oxidation of glycerol over AuPt/CeO2 catalysts

We synthesized a series of CeO2 with controllable morphologies including nanocube (NC), nanorod (NR), and nanopolyhedron (NP), enclosed by different facets, and then explored the support morphology effect on catalytic properties of Au1Pt3 catalysts in glycerol oxidation. As expected, the series of Au1Pt3/CeO2 catalysts exhibit a conspicuous support facet-dependent catalytic performance especially for the catalytic activity. Specifically, the TOF ranks in the order that Au1Pt3/NC (937.8 h−1) > Au1Pt3/NR (713.1 h−1) > Au1Pt3/NP (491.7 h−1). Among three catalysts, Au1Pt3/NC exhibits the most notable interaction strength due to the highest oxidizing capability of Ce6c–O2c sites on NC (1 0 0), confirmed by in situ CO FT-IR. In this case, Pt0 species are more easily oxidized to Pt2+. The strong metal–support interaction promotes the activation ability of oxygen, resulting in the generation of more reactive oxygen species including O2−, O22−, and O−, among which O2− is proved to be the most favorable species.

Co-catalyst free ethene dimerization over Zr-based metal-organic framework (UiO-67) functionalized with Ni and bipyridine

Ni functionalized metal organic frameworks (MOF) are promising heterogeneous ethene dimerization catalysts. Activities comparable to or higher than Ni-aluminosilicates have been reported in literature. However, unlike the Ni-aluminosilicates, those Ni-MOFs require a large excess of co-catalyst to initiate the dimerization process and some catalysts generate polymers which lead to catalyst deactivation. Herein, we report a series of Ni(II) and 2,2′-bipyridine-5,5′-dicarboxylate (bpy) functionalized UiO-67 MOF that catalyze the ethene dimerization reaction co-catalyst free. The catalysts were active for ethene dimerization (up to 850 mg butene gcat−1 h−1) after activation at 300 °C in 10 % O2 for 360 min and subsequent exposure to flowing ethene (P(ethene) =26 bar, 250 °C) for 240 min. The catalysts yielded up to 6 % conversion with 99 % selectivity to linear 1- and 2-butenes, which formed in non-equilibrated ratios. Overall, the test data indicate that all three linear butenes are formed on a single active site, in accordance with the Cossee-Arlman mechanism. Ex situ XAS and CO FT-IR spectroscopy studies point towards Ni monomers or, plausibly, low-nuclearity Ni-multimers, docked at bpy linkers with Ni-Ni distances > 4 Å, as the main active site for the ethene dimerization reaction.

Platinum Catalyzed C–H Activation and the Effect of Metal–Support Interactions

Catalytic C–H bond activation of methane and ethane on a series of silica supported platinum catalysts (Pt/SiO2) was studied by using hydrogen/deuterium (H/D) exchange. Kinetic experiments demonstrate that under the reaction conditions studied, the rate of C–H bond activation shows approximate first order dependence in alkane and inverse first order dependence in D2. The rate of C–H activation is affected by the presence of sodium on the silica support, where sodium-free supports have the fastest rates of C–H activation, as assessed by H/D exchange. CO adsorption and FTIR studies indicate that the Pt particles on the sodium-free support are more electron-deficient, having the most blue-shifted linear CO stretch, while sodium-containing supports are more electron-donating, having the most red-shifted linear CO stretch. It is proposed, based on the results described in this article and previous work in the literature, that more electron-donating supports cause the Pt particles to be more electron-rich and t...

Effect of silicon content on active catalytic phase for hydrocracking of heavy crude oils

The silicon composition effect on acidic properties of Ni[sbond]Mo catalysts was investigated for hydrocracking reaction, where an optimal Si and Al ratio is required for the formation of Brønsted acid sites and as well as of Al3+ (IV) tetrahedral coordinated sites. The support composition affects the Si[sbond]OH[sbond]Al network, where cations (Al3+ or Si4+) have a coordination number of IV generating higher Brønsted acidity and macro-pores. The supports and fresh catalysts were characterized by atomic absorption, nitrogen physisorption, FT-IR of CO and pyridine adsorption and 27Al MAS NMR.

The MnO<sub>2</sub>/Zeolite NaY Catalyzed Oxidation of CO Emission in Catalytic Converter System

CO emission is one of biggest problem in environmental sector due to increasing number of motorcycle user in every years. CO is poison gas which directly affects on the public health and earth’s atmosphere. The aim of this research to developed catalyst in catalytic converter system to oxidize CO to CO2 by using MnO2/zeolite NaY. Zeolite NaY was synthesized by using hydrothermal method following by wet impregnation to form MnO2/zeolite NaY, then the composite was characterized by XRD, FTIR, SEM-EDX, N2 physisorption, and catalytic activity oxidation of CO was carried out using 4 tag motorcycle. The XRD result represent zeolite NaY synthetic has similar diffraction peak with zeolite NaY (JCPDS 39-1380), then infrared spectrum exhibit T-O-T at fingerprint area which exhibit vibration of zeolite NaY. Octahedral crystal was successfully observe by using SEM which represent zeolite NaY crystal similar with previous study. N2 physisorp shows that the composite has type IV of isotherm which exhibit the micropore and mesopore was form into material. Then, MnO2/zeolite NaY has good thermal stability as well as catalytic activity for CO oxidation, where the longer reaction time successfully to reduce the concentration of CO. Conversely, CO2 concentration dramatically increase as function of reaction time.

Highly active iridium–rhenium catalyst condensed on silica support for hydrogenolysis of glycerol to 1,3-propanediol

Increase of loading amount of Ir-ReOx/SiO2 catalyst up to 20 wt% of Ir enhanced the Ir-based activity in glycerol hydrogenolysis to 1,3-propanediol. The ratio of used precursor amount was set constant (Re/Ir = 1; “nominal” Re/Ir ratio); however, actual Re/Ir amount was lower at higher loading amount because of the loss of Re during calcination. The catalytic performance, reactivity of related substrates and kinetics over optimized Ir-ReOx/SiO2 (20 wt%-Ir, Re/Ir = 0.34, actual) was compared with the previously reported catalyst (4 wt%-Ir, Re/Ir = 1, nominal; Re/Ir = 0.83, actual) without H2SO4 addition which increases the activity and stability of 4 wt%-Ir Ir-ReOx/SiO2 catalyst. High 1,3-propanediol selectivity (ca. 70%) was obtained over 20 wt%-Ir Ir-ReOx/SiO2 at 20% conversion level of glycerol. This high selectivity was almost independent of glycerol concentrations, while 4 wt%-Ir Ir-ReOx/SiO2 catalyst showed lower selectivity when glycerol concentration was lower. The 20 wt%-Ir Ir-ReOx/SiO2 exhibited good reusability under optimized reaction conditions when recovered without exposure to air. Small Ir metal particles (˜3 nm) were observed from both XRD and TEM regardless of high Ir loading amount. The results of XANES and EXAFS suggested high reduction degree of Re species (˜80%); however, further characterization of XRD and CO FT-IR supported the absence of Ir-Re alloy. Combined with TPR and CO adsorption results, we proposed that ReOx cluster at low average valence (ca. + 1˜+2) was attached to Ir metal. This unique structure decreased the effect of SiO2 support and increased the number of active sites, accounting for higher activity. The heterolytic dissociation of hydrogen molecule (˜+1 reaction order on H2 pressure) and strong interaction between glycerol and catalyst surface (˜0 reaction order on glycerol concentration around standard reaction conditions, 67 wt% glycerol solution) were suggested for 20 wt%-Ir Ir-ReOx/SiO2 catalyst. This 20 wt%-Ir Ir-ReOx/SiO2 catalyst can be also applied to various substrates with OCCH2OH structure for the selective cleavage of the CO bond.

Supported Co-Re Bimetallic Catalysts with Different Structures as Efficient Catalysts for Hydrogenation of Citral.

Bimetallic Co-Re/TiO2 catalysts were developed for efficient citral hydrogenation. Bimetallic catalysts were prepared by co-impregnation (CI), successive-impregnation (SI), and surface redox method (SR). The arrangement between the Co and Re species on these systems was fully characterized using several techniques (TEM-energy-dispersive X-ray spectroscopy, H2 temperature-programmed reduction, temperature-programmed desorption, XRD, CO FTIR spectroscopy, model reaction of cyclohexane dehydrogenation), and their catalytic performances were evaluated for the selective hydrogenation of citral towards unsaturated alcohols. The Re and Co species are completely isolated in the CI sample, presenting a very limited Co-Re interaction. In SI samples, the metals coexist in a Janus-type structure with a concentration of Re around Co. Decoration/core-shell structures are observed for SR samples resulting from the redox exchange between the metallic surface of the parent Co/TiO2 catalyst and the Re7+ species of the modifier precursor salt. The contact degree between the two metals gradually increases as follows: Isolated structure (CI)<Janus-type structure(SI)<decoration/core-shell structure (SR). The unchanging structure of all SI samples independent of the Re loading leads to similar electron transfer, and the increase in Re content results in agglomeration of Re, thus decreasing the catalytic activity. Density-of-state (DOS) calculations prove that the high valence of Re is a disadvantage for the hydrogenation reaction. For SR samples, the increase of Re loading contributes to the electron transfer from Re to Co that is consistent with a change of structure from decoration to core-shell. The lack of directly accessible Co atoms for SR catalysts with fully coated structure decreases the efficiency of Re reduction. The presence of Co-Re interaction resulting from the close contact between metals plays a dominant role in the hydrogenation of citral. Nevertheless, an excessively high contact degree is unnecessary for citral hydrogenation once Co-Re interaction has formed.

Catalytic assessment of nanostructured Pt/xLa2O3-Al2O3 oxides for hydrogen production by dry reforming of methane: Effects of the lanthana content on the catalytic activity

Abstract The effects of the lanthana content on the textural and structural properties of nanostructured Pt/xLa2O3-Al2O3 were studied. All catalysts were prepared by the sol-gel method using appropriate Al and La precursors. 1 wt.% of platinum was incorporated into the solids. The catalysts were investigated in detail by means of several characterization techniques such as XRD, ICP-OES, 27Al MAS NMR, N2 physisorption isotherms, HRTEM, XPS, TPR as well as CO DRIFTS, Raman and FTIR spectroscopy. The results show that an increased activity during the dry reforming of methane was achivied due to the ability of the [LaPtOx]Pt0-like entity to eliminate the coke. The accessibility of Pt species to methane and to carbon dioxide promoted the reaction by adding an optimum La2O3 content of 12 wt.%.

Selective oxidation of n-octanol on unmodified and La-modified nanogold catalysts: Effect of metal content

We investigated the influence of metal loading in gold catalysts supported on titania, either unmodified or La-modified, on their catalytic performance and the formation of active sites for selective oxidation of n-octanol under mild conditions. Catalysts were characterized by BET, EDX, ICP, HRTEM, FTIR CO and XPS. Gold content had a significant effect on the catalytic properties of unmodified catalysts: activity of Au/TiO2 increased by increasing the metal load. However, in the case of a lanthanum-modified support samples, an increase of gold content from 0.5 to 4 wt.% had no effect on its activity (ca. 40% conversion after 6 h for all catalysts). This catalytic behavior is due to a change in the surface concentration of Au+ ions. For the unmodified catalysts, the surface concentration of Au+ ions increased with increasing gold loading, and, as a consequence, a significant increase in activity was observed. For La-modified catalysts, the surface concentration of Au+ ions is almost the same for all gold concentrations; as a result, no increase in activity was observed with the increase in gold content. It points to Au+ ions as the most probable active sites for the studied reaction.

(Invited) Surface Sites Probing and Electrocatalytic Property of Atomic Sub-Monolayer and Multilayer on Tetrahexahedral Nanocrystals

Tetrahexahedral nanocrystals (THH NCs) of fcc metals such as Pt, Pd, Rh possess a high catalytic activity due to their open surface structure and high surface energy.1 It has been determined that the THH Pt NCs are enclosed by {hk0} facets that can be decomposed with different subfacets. As an example, the most frequently prepared THH Pt NCs are bounded with {730} facets, which can be decomposed into (310) + 2(210) or 3(100)´(110) + 2(100)´(110) + 2(100)´(110). 1,2 It is obvious that the high catalytic activity of the THH Pt NCs originates from the high density of surface active sites. In the current study through applying cyclic voltammetry (CV) and in situ FTIR spectroscopy, CO adsorption and oxidation were used as probe reactions to investigate the surface sites on THH Pt NCs, in order to understand their role in practical electrocatalysis. Furthermore, the electrocatalytic property towards small organic fuel molecule oxidation of sub-monolayer of adatoms as Bi, Ru and Au on THH Pt NCs, and multi Pt atomic layer on THH Pd NCs were studied to gain knowledge on surface structure effects of high-index faceted nanocrystals in electrocatalysis. Acknowledgement: This work was supported by Natural Science Foundation of China (21573183, 21621091).

Kinetics and mechanisms of coal oxidation mass gain phenomenon by TG–FTIR and in situ IR analysis

Coal spontaneous combustion occurs frequently in mining and utilizing processes, which mostly result from the complex dynamic reaction of coal and oxygen. With a focus on the mass gain phenomenon of coal oxidation observed by thermogravimetric analysis, TG–FTIR and in situ IR experiments for a typical Jurassic coal in West China were carried out to identify the kinetics and mechanisms of coal oxidation. The results showed that a mass loss existed both in coal oxidation and pyrolysis process, but the phenomenon of mass gain was particular in coal oxidation process. By FTIR analysis, CO and CO2 produced in the oxidation process were more than those in the pyrolysis process. By Ozawa method, the apparent activation energy at the initial temperature of mass gain stage was determined to be 43.17 kJ mol−1, which was much less than that at the end temperature of 122.0 kJ mol−1. With in situ IR analysis of Liangshuijing coal during the oxidation and pyrolysis process, the oxidation mass gain mechanism was discussed. It was concluded that the key functional groups for this typical coal oxidation mass gain were carboxyl and carbonyl.

Cs2.5H0.5PW12O40 Encapsulated in Metal–Organic Framework UiO-66 as Heterogeneous Catalysts for Acidolysis of Soybean Oil

The Keggin-type Cs2.5H0.5PW12O40 was encapsulated in metal–organic framework UiO-66 by a simple solvothermal synthesis method. The characterization results showed that the morphology and crystal structure of UiO-66 were preserved, and the heteropolyanion structure remained unchanged after Cs2.5H0.5PW12O40 encapsulation. The prepared Cs2.5H0.5PW12O40@UiO-66 material has demonstrated to be an environmentally benign catalyst in the acidolysis of soybean oil with medium-chain fatty acids for the production of low-calorie structured lipids. The FT-IR CO adsorption experiments revealed that additional Lewis acid sites were formed in the solid acid catalyst, which were essential to catalyze the acidolysis reaction. The solid catalyst could be reused for several recycles without obvious deactivation due to hardly leaching of active components into the reaction mixture.