Chemisorption Of NO Research Articles

Quantum Dynamics and Quasi-Classical Trajectory Study for the Dissociative Chemisorption of NO on Cu(111)

Quantum Dynamics and Quasi-Classical Trajectory Study for the Dissociative Chemisorption of NO on Cu(111)

Development of CuO/ZnO/Al2O3-hydrotalcite −based catalysts for middle temperature water gas shift reaction: Impact of calcination temperature and residual carbonates

A series of Cu/ZnO/Al2O3 catalysts are synthesized using a reverse co-precipitation method and subjected to calcination at different temperatures ranging from 300 to 650 °C. Characterization of the resulting powders is carried out through ICP, N2-physisorption, XRD, TGA, H2-TPR, N2O chemisorption and SEM techniques. Subsequently, the catalytic performance of the final samples is assessed in the medium-temperature water gas shift reaction across a broad temperature range from 200 to 330 °C. The precursor predominantly featured a hydrotalcite-like structure, undergoing decomposition through three main stages by losing structural H2O and CO2 molecules. All catalysts demonstrated stable performance without by-products during accelerated aging under reaction conditions. The results revealed that the partial elimination of carbonate ions at 300 °C resulted in easily reducible and consequently less thermally stable active sites. For calcined samples at 450 °C and 550 °C the thermal sintering played a pivotal role, leading the less copper surface area and subsequently higher CO slip values. In the case of the calcined sample at 650 °C, despite larger CuO and ZnO crystals, a trade-off between the emission of high-temperature carbonates and thermal sintering led to acceptable activity and thermal stability. Ultimately, the highest Cu surface are of 222 m2gr cat −1 along with the lowest amount of CO slip are observed for calcined sample at 350 °C, attributed to an optimal amount of carbonate, resulting in the superior catalytic performance. This effective balance between thermal sintering and the amount of residual carbonates yielded a final catalyst with outstanding activity and stable performance.

Adsorption and sensing performances of greenhouse gases (CO2，CH4，SF6, N2O) on Ni modified GeSe surface

The greenhouse effect has drawn significant recent attention due to its serious impact on Earth's climate and ecosystems. Therefore, this study investigates the adsorption and sensing properties of four greenhouse gases (CH4, CO2, SF6, and N2O) on the Ni-GeSe monolayer using first principles of DFT. The doping behavior of Ni on intrinsic GeSe monolayer is initially studied and the most stable doping structure is selected. Then the adsorption energies, adsorption distances, charge transfers, energy band structures, molecular frontier orbitals and recovery times of the selected Ni-GeSe structure with the four greenhouse gases are analyzed and compared. The results show that Ni modification can improve the surface activity of the intrinsic GeSe monolayers, thereby improving their adsorption and sensing properties. Ni-GeSe has weak adsorption of CH4 and CO2, while strong chemisorption of SF6 and N2O, making it suitable as an adsorbent for these two gases. Analysis of the recycling performance of Ni-GeSe monolayers shows that Ni-GeSe has a good recovery time for N2O at a temperature of 398 K, suggesting its potential as an efficient low-power resistive N2O gas sensor. And gas sensors based on GeSe and its modified materials can be theoretically guided by these calculations.

Boosting DeNOx performance via magnetic enhancement in synergistically-optimized γ-Fe2O3-CuO composite oxides

Fe or Cu oxides and their composites are cost-effective yet seldom used in DeNOx because they deactivate easily. Doping/supporting enhances activity but increases synthesis complexity and cost. Here, we present a γ-Fe2O3-CuO composite oxide with a high synergy created through co-oxidation, which upon magnetization, exhibits further enhanced DeNOx activity. Detailed quasi in-situ XRD and in-situ DRIFTS analyses indicate that in Fe-Cu composite oxides, iron species inhibit the full reduction of Cu2+ to Cu0, while copper counters the formation of inactive α-Fe2O3, contributing to the γ-Fe2O3-CuO composite’s enhanced stability during reactions. Fascinatingly, pre- and post-magnetization XPS and in-situ DRIFTS analyses demonstrate the magnetic field’s role in promoting the chemisorption of both oxygen and NO, thereby enhancing DeNOx efficiency. This research not only achieves the synergistic coupling of copper and iron oxides and sheds light on the deactivation processes of their pure species but also serves as a pioneering exploration of magnetic manipulation in catalyst design, laying a foundation for future technological advancements.

Enhancing the catalytic performance of Cu/ZnO/Al2O3 catalyst in methanol synthesis from biomass‐derived syngas with CeO2, MnO2 and ZrO2 as promoters

AbstractThe performance of Cu/ZnO/Al2O3 (CZA) catalysts promoted by addition of CeO2, MnO2 or ZrO2 in direct methanol production from unconventional syngas was experimentally investigated. The unconventional syngas used in this study contain 25% H2, 25% CO, 20% CH4, 20% CO2 and 10% N2, representing biomass‐derived syngas cultivated from an industrial wood chips pyrolysis plant. The catalysts were synthesised using co‐precipitation technique and tested for methanol synthesis in a fixed‐bed reactor. The activity test of the catalysts showed that the addition of CeO2 or ZrO2 to the CZA catalyst improved the methanol yield, albeit with lower selectivity, whereas adding MnO2 enhanced methanol selectivity but decreased the methanol yield. ZrO2‐promoted catalyst showed the best‐improved activity and stability. The calcined and spent catalysts were characterised using X‐ray diffraction (XRD), N2 physisorption, N2O chemisorption, hydrogen temperature‐programmed reduction (H2‐TPR) and X‐ray photoelectron spectroscopy (XPS). The characterisation results indicate that the catalytic activity is dependent on Cu dispersion, Cu‐active surface area, the catalyst reducibility, Brunauer–Emmett–Teller (BET) surface area and the Cu0/Cu+ ratio. In contrast, catalyst stability was related to the proportion of Cu+ among all surface Cu species.

Effect of oxygen-containing groups in functionalized graphene on its gas sensing properties

The creation of active material for chemiresistive gas sensors with high selectivity and sensitivity will allow a step towards miniaturization and reduction of power consumption of portable gas sensors. Graphene is a promising platform for the synthesis of two-dimensional active materials with high sensitivity. In this work, applying density functional theory (DFT) calculations, the effect of oxygen-containing functional groups (O, OH, O, COOH) on the adsorption of small gas molecules (NH3, CO2, CO, H2S, NO2, SO2) was rigorously studied. Based on the adsorption energies and partial charges from DFT calculations, the sensitivity and selectivity of graphene with different functionalizations were predicted. It was found that hydroxyl and carboxyl groups demonstrate increased selectivity and sensitivity of gas sensors, and the edge of graphene with hydroxyl groups shows the highest enhancement. Graphene with a carbonyl group was found to undergo irreversible chemisorption of NO2, which can potentially cause active material degradation, limiting the recyclability of gas sensors. Most of the molecules show both donor and acceptor behavior, which highlights the importance of a thorough selection of specific functional group types. The obtained results are useful for the rational design of graphene-based active material with oxygen-containing functional groups for chemiresistive gas sensors.

A Blyholder mechanism in the chemisorption of N2O on Ni(111) – studied with Auger-photoelectron coincidence spectroscopy

In heterogeneous catalysis the surface-adsorbate bond strength is critical for the function of the system. Here we study a series consisting of multilayer, bilayer and monolayer N2O on Ni(111) and employ Auger-photoelectron coincidence spectroscopy (APECS) to study the interaction between the molecule and the substrate directly. We observe intensity in the nitrogen Auger spectra that arise from the interaction between molecule and surface (not observed in free molecules) whereas the oxygen spectra are thickness-independent. Since the two nitrogen atoms of N2O are chemically inequivalent we can assign the intensity present in the bilayer and monolayer cases to orbitals centered on the terminal nitrogen which is closest to the Ni(111) surface. Using ab initio, molecular dynamics and solid-state density functional theory calculations we infer a Blyholder model of the surface bond as consisting of donation from the terminal nitrogen lone-pair valence orbital with back-donation from the metal into the unoccupied orbitals on that nitrogen. This coincidence technique can readily be used to study substrate–adsorbate interactions directly with chemical and orbital specificity — this opens up prospects to study fundamental steps of molecular adsorption and heterogeneous catalysis with unprecedented detail.

Design high performance field-effect, strain/gas sensors of novel 2D penta-like Pd2P2SeX (X= O, S, Te) pin-junction nanodevices: A study of transport properties

In the realm of modern nanodevices, attaining high-switching performance and fulfilling sensing detection functions in high-precision environments are of paramount importance. Two-dimensional (2D) Pd2P2SeX (X = O, S, Te) have excellent geometric, physical, and chemical characteristics, and can crystallize into orthogonal structures with indirect band gaps. Based on these fundamental properties, 2D Pd2P2SeX pin-junction devices were modeled via first principles to simulate field-effect transistors, strain sensors with high-switching ratios, and chemisorption-based gas sensors. The Pd2P2SeX pin-junction device exhibited significant gate-voltage control over current, with current changes over nearly three orders of magnitude for Pd2P2SeO. Moreover, the application of a biaxial strain could close the band gap of Pd2P2SeX and significantly enhance transport characteristics, leading to substantial switching effects in devices, such as a 1.44 × 108 switching ratio for Pd2P2SeS. The chemisorption of NO and NO2 produced interfacial electronic coupling that generated an impurity band crossing the Fermi level, thereby inducing a semiconducting to metallic transition. Pd2P2SeO- and Pd2P2SeS-based pin-junction devices exhibited 49.01 and 23.80 s recovery times, respectively, when detecting NO and NO2. Hence, they could be used as high-sensitivity and -selectivity gas sensors. Overall, 2D Pd2P2SeX materials have a vast potential for the development of low-dimensional electronic devices.

Highly efficient CO2 hydrogenation to methanol over Cu–Ce1-xZrxO2 catalysts prepared by an eco-friendly and facile solid-phase grinding method

In this study, a series of Cu–Ce1-xZrxO2 (x = 0, 0.2, 0.5, 0.8, 1) catalysts were prepared by an eco-friendly and facile solid-phase grinding method. The effect of different Ce/Zr molar ratios on the performance of Cu–Ce1-xZrxO2 catalysts for CO2 hydrogenation to methanol was investigated. The results showed that the Cu–Ce0.5Zr0·5O2 catalyst had the best catalytic performance, with CO2 conversion of 15.2 % and methanol yield of 7.5 % at GHSV = 3600 mL/(gcat·h)); when GHSV was increased to 20,000 mL/(gcat·h), the space-time yield of methanol reached 270.8 gCH3OH/(kgcat·h). X-ray diffraction (XRD), scanning electron microscope (SEM), N2 adsorption-desorption, N2O chemisorption, X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction by H2 (H2-TPR), and temperature programmed desorption (H2-TPD, CO2-TPD) techniques were used to characterize the catalysts, and the higher reactivity of Cu–Ce0.5Zr0·5O2 can be attributed to more Cu0 species, defect oxygen and basic sites. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) results revealed that the hydrogenation of CO2 to methanol occurred through the formate intermediate pathway. This work proposed an eco-friendly and facile method for the preparation of high-performance Cu-based catalysts and the systematic study provided a deep insight for the development of high-performance Cu-based catalysts for methanol synthesis from CO2 hydrogenation.

Adsorption behavior of Rh-doped graphdiyne monolayer towards various gases: A quantum mechanical analysis

In this study, the conformational properties of pure Graphdiyne (GDY) and Rh-doped (Rh-GDY) for the CO, NO, and NH3 gases are investigated using DFT computations. The doping site is optimized, and the structure parameters and electronic properties of Rh-GDY were evaluated. It is found that Rh-dosing at the optimal site (CII) increases the electrical conductivity due to decreasing of gap energy. The tendency of pure GDY toward CO, NO, and NH3 gases is low and not suitable for sensing due to physical adsorption of gases. However, Rh-GDY demonstrates exceptional performance as a gas sensor due to its strong chemisorption of CO, NO, and NH3 gases through hybridization and chemical reactions with the gas molecular orbital. As a result, Rh-GDY represents a potential gas detection sensor material with notable monitoring capabilities for gases such as CO, NO, and NH3. This research provides valuable information for advancing the creation of innovative and effective gas detection sensor technologies.

On the scope of mechanochemical activation: The case of Cu/ZnO catalytic systems

ZnO was submitted to different conditions of high-energy ball milling to thoroughly study the outcome of mechanochemical activation. Structural modifications led to a decrease in crystallite size and an increase in micro-strain and specific surface area (SBET) with milling time. Different copper amounts were added on pristine (reference) and activated support by incipient wetness impregnation. Cu deposited over activated support showed an enhanced metal-support interaction since part of Cu2+ could be introduced into milled ZnO lattice, replacing Zn2+ ions and/or locating in lattice interstitials. Moreover, further analyses suggested an electron transfer from activated support to metal, generating a mixture of Cu2O–CuO species, particularly at the interface between metal and support. N2O chemisorption studies gave Cu particle sizes of 1.3, 1.9 and 3.5 nm (for 0.2, 0.5 and 1 wt% Cu, respectively) and thus a good metal dispersion over ZnO was achieved. Hence, support's activation by milling process showed to be an excellent approach to improve both metal-support interaction and metal dispersion of supported catalysts.

Glass-fiber catalysts for selective catalytic reduction of nitrogen oxides by CO and hydrocarbons

Glass-fiber catalysts (GFCs) are investigated in the process of the catalytic reduction of nitrogen oxides by hydrocarbons and carbon monoxide contained in waste and flue gases. Studies show that the platinum-based GFCs prepared by surface high-temperature synthesis approach demonstrates higher activity in the reactions of NOx reduction and CO and CxHy oxidation, in comparison with conventional GFCs and catalytic systems based on oxides of MnCe and FeV. Structured cartridges with a corrugated and flat metal mesh with longitudinal flow direction and satin type GFC were found to provide the highest apparent catalyst activity. The kinetic model for Pt/GFC was proposed based on the experimental data. The best kinetic description is provided under account of formation of nitrite-nitrate surface compounds resulting from NO chemisorption and further interaction of these compounds with CO, as well as under account of simultaneous catalytic and non-catalytic oxidation of propane by oxygen both to CO and CO2. The proposed model may adequately reproduce the non-trivial experimental regularities, such as CO and NO conversion decrease at high temperatures and synergetic effect of oxygen on the rate of NO reduction by CO.

Supported Cu catalysts on UiO-66 toward enhanced methanol selectivity by CO2 hydrogenation: Effect of Cu loading

The xCu/MOF catalysts were synthesized by incipient-wetness impregnation of copper precursor on UiO-66 support, in which the Cu loadings were 5, 10, and 20% (wt.%). To gain insight into the properties of the materials, a range of techniques, including XRD, TEM, TGA, N2 physisorption, CO2-TPD, EDS, N2O chemisorption, XPS, IR, and NMR, were employed. The effectiveness of catalysts was evaluated for synthesizing methanol through CO2 hydrogenation under various Gas Hourly Space Velocities (GHSVs) and reaction conditions, including pressures of 10 and 30 bar, CO2/H2 ratios of 1:3, and CO2/H2/N2 ratios of 1:3:0.14 M, all conducted at a temperature of 250 °C. The active site in the Cu/UiO-66 catalyst is the interface between Cu+ nanoparticles (NPs) with Zr oxide SBU [Zr6O4(OH)4(−CO2) and the defects related to unsaturated Zr sites of the Zr-Oxo cluster due to the increase of Cu NPs occupying missing linker defects of the MOF structure. 20Cu/MOF catalyst, with the highest copper loading, showed the best methanol formation rate and CO2 conversion due to the strong metal-support interaction and the highest amount of the missing linker defects of the MOF structure.

Coal/NH3 interactions during co-pyrolysis and their effects on the char reactivity for NO-reduction: A ReaxFF MD study

In this work, the interactions between NH3 and coal during co-pyrolysis and their influences on char structure and char reactivity for NO reduction are investigated using reactive molecular dynamic (ReaxFF MD) simulations, revealing that coal promotes the thermal decomposition of NH3 because it provides H radicals to attack the N-H bonds in NH3. The primary pyrolysis reactions (thermal breaking of weak covalent bonds) of coal are inhibited by NH3·NH3 also influences the secondary reactions in coal pyrolysis through two aspects: (1) promotes tar cracking to generate gas, and (2) inhibits the polymerization of tar to form char. Compared with coal pyrolysis, the H/C ratio of char and number of O and N atoms in char decrease more slowly during coal/NH3 co-pyrolysis. However, NH3 has little influence on the release of H2S. The effect of NH3 on the physicochemical properties of the char is then analyzed. The oxygen atoms are present mainly as hydroxyl, ether, and carbonyl forms, and the nitrogen atoms are present mainly as cyanide and amino forms in both coal pyrolysis char and coal/NH3 co-pyrolysis char. The coal/NH3 co-pyrolysis char has lower helium density, lower graphitization degree, and larger pores compared with coal pyrolysis char. Finally, the reactivity of coal pyrolysis char and coal/NH3 co-pyrolysis char for NO reduction are examined. The coal/NH3 co-pyrolysis char is more conducive to NO chemisorption and N2 generation. Using a first-order kinetics model, the activation energy of NO reduction reactions on coal pyrolysis char and coal/NH3 co-pyrolysis char are determined as 180 and 123 kJ/mol, respectively.

Effect of the surface termination on the adsorption of flue gas by the titanium carbide MXene

Depending on the synthesis and/or post-treatment method, MXenes become covered by surface terminations. Here, via calculations based on density functional theory, we investigate how suitable the Ti2C MXene, with nine different termination possibilities (none, Br, Cl, F, H, NH, O, OH, or S), is for adsorbing 12 flue gas molecules, namely, CH4, CO, CO2, H2, H2O, H2S, N2, NH3, NO, O2, SO2, and SO3. According to our results, a general rule is that stronger adsorption is associated to more charge transferred between the adsorbent and the adsorbate. The clean Ti2C MXene is very reactive and spontaneously dissociates nearly half the species considered. H and F surface terminations are locally replaced by O in the presence of O2 since its dissociation on Ti2CH2 or Ti2CF2 is energetically cheap and exothermic. The Ti2C(OH)2 surface is damaged by the adsorption of NO, O2, SO2, or SO3 because they bind the H atoms of hydroxyl groups and locally create O terminations. Ti2CO2 and Ti2CS2 are selective toward the chemisorption of NH3 and NO, respectively, with adsorption energies suitable for adsorption/separation applications. The Ti2CBr2, Ti2CCl2, and Ti2C(NH)2 surfaces physisorb all the investigated molecules, with binding energies that qualitatively correlate with their van der Waals volumes, thus having potential for application in reusable gas storage.

The Activity and Stability of Promoted Cu/ZnO/Al2O3 Catalyst for CO2 Hydrogenation to Methanol

Cu/ZnO/Al2O3 catalyst with the addition of tri-promoters (Mn/Nb/Zr) was investigated with respect to their catalytic activity and stability in a prolonged reaction duration in methanol synthesis. Spent catalysts were characterized using N2 adsorption-desorption, FESEM/EDX, TEM, N2O chemisorption, and XPS for their physicochemical properties. The catalyst longevity study was evaluated at two days, seven days, and 14 days at 300 °C, 31.25 bar, 2160 mL/g.hr GHSV, and H2:CO2 at 10:1. The CO2 conversion and methanol yield decreased by about 5.7% and 7.7%, respectively, when the reaction duration was prolonged to 14 days. A slight reduction in catalytic activity under prolonged reaction duration was found due to thermal degradation.

Highly active and stable MoS2-TiO2 nanocomposite catalyst for slurry-phase phenanthrene hydrogenation

MoS2-TiO2 nanocomposite catalysts with Janus structure were synthesized via facile one-step solvothermal method. X-ray diffraction, high resolution transmission electron microscope, NO chemisorption and X-ray photoelectron spectroscopy were applied to characterize the composition and nanostructure of the MoS2-TiO2 nanocomposite catalysts. Experimental results revealed that the MoS2-TiO2 nanocomposite catalysts with Janus structure were composed of MoS2 layers (few stacked layers of 1–3 and short slabs of 2–10 nm) and TiO2 nanoparticles (10–15 nm), which have strong MoS2-TiO2 interaction with transferring electrons from TiO2 to MoS2. Catalytic performance of MoS2-TiO2 nanocomposite catalysts for phenanthrene hydrogenation was investigated and compared with that of MoS2 catalyst in an autoclave reactor with high temperature and high pressure. The phenanthrene conversion over the MoS2-TiO2 nanocomposite catalyst with MoS2 content of 15.0 wt% (MoS2-TiO2-15) can reach 91.6%, which was much higher than 50.4% for MoS2 catalyst and 76.8% for conventional supported MoS2/TiO2-15 catalyst. After 7 cycles of phenanthrene hydrogenation reaction, the phenanthrene conversion over MoS2-TiO2-15 nanocatalyst remained at 68.6%, while the phenanthrene conversion over MoS2 catalyst was reduced to only 25.4%. The MoS2-TiO2 nanocomposite catalysts exhibit significantly enhanced catalytic activity and stability for slurry phase hydrogenation. The enhanced catalytic activity originates from the exposure of abundant coordinatively unsaturated Mo atoms. The enhanced stability results from the Janus structure with stable MoS2-TiO2 interaction and Mo–O–Ti bonds, which anchor MoS2 layers on the surface of TiO2 nanoparticles to avoid the curling, folding and agglomeration of MoS2 layers. This is an important finding on slurry phase catalytic hydrogenation performances of MoS2-based nanocomposite catalysts with Janus structure. Shedding light on the research of Janus nanocomposite catalysts in catalytic hydrogenation is significantly crucial for the development of effective and stable hydrogenation catalysts.

Novel application of sodium manganese oxide in removing acidic gases in ambient conditions

In this study, we have demonstrated the application of sodium manganese oxide for the chemisorption of toxic acidic gases at room temperature. The fabricated alkali ceramic has Na0.4MnO2, Na2Mn3O7, and NaxMnO2 phases with a surface area of 2.6 m2 g–1. Na-Mn oxide was studied for oxidation of H2S, SO2, and NO2 gases in the concentration range of 100–500 ppm. The material exhibited a high uptake capacity of 7.13, 0.75, and 0.53 mmol g–1 for H2S, SO2, and NO2 in wet conditions, respectively. The material was reusable when regenerated simply by soaking the spent oxide in a NaOH-H2O2 solution. While the H2S chemisorption process was accompanied by sulfide, sulfur, and sulfate formation, the SO2 chemisorption process yielded only sulfate ions. The NO2 chemisorption process was accomplished by its conversion to nitrite and nitrate ions. Thus, the present work is one of the first reports on alkali ceramic utilization for room-temperature mineralization of acidic gases.

Comparative study of carbon-deNOx process by different sewage sludge chars

Sewage sludge char (SC) reduces NO to N2 at high temperatures thus acting as a potential reducing agent in flue gas cleaning systems. However, SC needs to be modified to enhance the carbon-deNOx performance. In this study, coal char (CC) and different types of SCs, i.e., original (SC-R), pyrolytic volatiles activated (SC–V) and KOH activated (SC–K), were compared in terms of their carbon-deNOx performance, including NO removal rate and secondary pollution discharged. The results showed that when the oxygen content in the flue gas was 5–6%, the carbon-deNOx efficiency of the three types of SCs was greater than 70%, which was higher than that of the CC. SC-V has lower emissions of CO and gaseous nitrogen-containing compounds (NH3, HNCO, HCN) among the three types of SCs. For the oxygen content of 8–11% in the flue gases, the NO conversion performance was found in the order of SC-K > SC-R > SC-V > CC. The physical and chemical characterization of activated carbon shows that pyrolytic-volatile activation increases the ratio of C–O and C=O functional groups on its surface of SC-V, which not only facilitates the chemisorption of NO but are also easily converted under high oxygen conditions. SC-V is found as a suitable reductant for carbon-deNOx within the temperature range of 300–350 °C.

Effect of glucose pretreatment on Cu-ZnO-Al2O3 catalyzed CO2 hydrogenation to methanol.

A series of Cu-ZnO-Al2O3 catalysts (CZA) were prepared by glucose pretreatment and applied for methanol synthesis from CO2 hydrogenation. The advantages of the glucose pretreatment and the effects of glucose content were investigated by XRD, N2 physisorption, SEM, N2O chemisorption, CO2-TPD, H2-TPR, TG, and XPS characterization techniques. The influence of glucose pretreatment on the average Cu particle size and the interaction between different components, as well as the effects of the amount of glucose on the Cu specific surface area, the ratio of Cu0/Cu+ and the performance of the catalysts were discussed. The results showed that the catalysts prepared by glucose pretreatment increased the number of basic sites and had a significant advantage in methanol yield. The optimum content of glucose was beneficial to improve the catalytic performance of the CZA catalyst. The maximum space-time yield of methanol was obtained by 2 wt% glucose pretreatments at 200 °C, which was 57.0 g kg-1 h-1.