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Journal of the American Chemical Society 143(43), 18216 - 18232 (2021). doi:10.1021/jacs.1c07874, Extended anionic frameworks based on condensation of polyhedral main group non-metal anions offer a wide range of structure types. Despite the widespread chemistry and earth abundance of phosphates and silicates, there are no reports of extended ultraphosphate anions with lithium. We describe the lithium ultraphosphates Li$_3$P$_5$O$_{14}$ and Li$_4$P$_6$O$_{17}$ based on extended layers and chains of phosphate, respectively. Li$_3$P$_5$O$_{14}$ presents a complex structure containing infinite ultraphosphate layers with 12-membered rings that are stacked alternately with lithium polyhedral layers. Two distinct vacant tetrahedral sites were identified at the end of two distinct finite Li$_6$O_{16}$^{26���}$ chains. Li$_4$P$_6$O$_{17}$ features a new type of loop-branched chain defined by six PO43��� tetrahedra. The ionic conductivities and electrochemical properties of Li$_3$P$_5$O$_{14}$ were examined by impedance spectroscopy combined with DC polarization, NMR spectroscopy, and galvanostatic plating/stripping measurements. The structure of Li$_3$P$_5$O$_{14}$ enables three-dimensional lithium migration that affords the highest ionic conductivity (8.5(5) �� 10$^{���7}$ S cm$^{���1}$ at room temperature for bulk), comparable to that of commercialized LiPON glass thin film electrolytes, and lowest activation energy (0.43(7) eV) among all reported ternary Li���P���O phases. Both new lithium ultraphosphates are predicted to have high thermodynamic stability against oxidation, especially Li$_3$P$_5$O$_{14}$ which is predicted to be stable to 4.8 V, significantly higher than that of LiPON and other solid electrolytes. The condensed phosphate units defining these ultraphosphate structures offer a new route to optimize the interplay of conductivity and electrochemical stability required, for example, in cathode coatings for lithium ion batteries., Published by American Chemical Society, Washington, DC

Due to its toxicity and corrosiveness, it is of enormous significance to efficiently capture and recover sulfur dioxide (SO2) from flue gas and natural gas. Herein, a new type of IL/MIL-0.7 composite was precisely designed to meet this challenge, which exhibits a high adsorption capacity for SO2 (13.17 mmol·g-1) at 298 K and 1 bar while excludes almost completely carbon dioxide (CO2) (0.27 mmol·g-1) and nitrogen (N2) (0.07 mmol·g-1). The high IAST selectivity (at least 11925) of IL/MIL-0.7 for SO2/CO2 can be achieved within the whole test pressure range. In addition, the breakthrough experiment also confirmed the excellent performance of the composite for deep removal of 2000 ppm SO2. Furthermore, the IL/MIL-0.7 composites can maintain excellent performance after four adsorption and desorption circulations and the thermostability can up to ~450 K. Therefore, this stable IL@MOF composite has the potential application as an effective adsorbent for SO2 removal from flue gas.

We report a new polymorph of lithium aluminum pyrophosphate, LiAlP2O7, discovered through a computationally guided synthetic exploration of the Li-Mg-Al-P-O phase field. The new polymorph formed at 973 K, and the crystal structure, solved by single-crystal X-ray diffraction, adopts the orthorhombic space group Cmcm with a = 5.1140(9) A, b = 8.2042(13) A, c = 11.565(3) A, and V = 485.22(17) A3. It has a three-dimensional framework structure that is different from that found in other LiMIIIP2O7 materials. It transforms to the known monoclinic form (space group P21) above ∼1023 K. Density functional theory (DFT) calculations show that the new polymorph is the most stable low-temperature structure for this composition among the seven known structure types in the AIMIIIP2O7 (A = alkali metal) families. Although the bulk Li-ion conductivity is low, as determined from alternating-current impedance spectroscopy and variable-temperature static 7Li NMR spectra, a detailed analysis of the topologies of all seven structure types through bond-valence-sum mapping suggests a potential avenue for enhancing the conductivity. The new polymorph exhibits long (>4 A) Li-Li distances, no Li vacancies, and an absence of Li pathways in the c direction, features that could contribute to the observed low Li-ion conductivity. In contrast, we found favorable Li-site topologies that could support long-range Li migration for two structure types with modest DFT total energies relative to the new polymorph. These promising structure types could possibly be accessed from innovative doping of the new polymorph.

We report a new polymorph of lithium aluminum pyrophosphate, LiAlP

Two mixed halogen borate–carbonates K9[B4O5(OH)4]3(CO3)X·7H2O (X = Cl, Br) have been successfully synthesized with the hydrothermal method. They crystallize in the space group P62c, and their stru...

Two polar molybdenum(VI) iodates(V), NH4[MoO3(IO3)] (1) and KRb[(MoO3)2(IO3)2] (2), have been prepared by a hydrothermal method. They crystallize in noncentrosymmetric (NCS) space groups Pna21 and ...

Three new complex borate compounds K7CaBi2B15O30, K7CaLa2B15O30 and K7BaBi2B15O30 have been synthesized by the high-temperature solution method. K7CaLa2B15O30 and K7CaBi2B15O30 crystallize in the chiral trigonal space group R32, while K7BaBi2B15O30 crystallizes in the noncentrosymmetric orthorhombic polar space group Pca21. All of the title compounds have similar three-dimensional crystal structures, which are composed of isolated B5O10 groups and LaO6 or BiO6 octahedra, and K+, Ca2+, and Ba2+ cations fill into the cavities to keep charge balance. Based on our research, in the system of K7MIIRE2B15O30 (MII = Ca, Sr, Ba, Zn, Cd, Pb, K/RE0.5; RE = Sc, Y, La, Gd, Lu, Bi), K7BaBi2B15O30 is unique and crystallizes in a different space group, which enriches the structural chemistry of borate. Detailed structural analyses indicate that the structural variation is due to the difference in size and coordination number of the alkaline-earth metal cations. Besides, UV-Vis-NIR spectroscopy analysis and the second-harmonic generation (SHG) measurement on the powder samples show that K7CaBi2B15O30 exhibits a UV cutoff edge (about 282 nm) and a moderate SHG response (about 0.6 × KDP). In addition, thermal analysis and infrared spectroscopy were also presented. To better understand the structure-property relationships of the title compounds, the first-principles calculations have been performed.

The diverse oxyfluoride species and vast number of different topological arrangements lead to fluorooxoborates’ structural beauty and richness. Herein, the first mixed alkali/alkaline-earth metal fluorooxoborate Ba3B10O17F2·0.1KF was successfully synthesized and systemically characterized. Its most important structural feature is an unprecedented double-layered B–O/F anionic arrangement.

Herein, we present the first lithium difluorophosphate LiPO2F2 exhibiting a unique polytetrahedral microporous architecture. The unique fluorine coordination environments and interlaced [LiO2]3- straight chains give rise to the neutral pore framework with a 10- membered ring channel along the crystallographic c axis. A variety of measurements have been adopted to systemically characterize LiPO2F2. This work contributes to the structural and functional diversity of phosphate chemistry by the exploration of fascinating difluorophosphates.

A new barium fluorooxoborate, BaB5O8F·xH2O (x ≈ 0.17), with two interesting independent three-dimensional B–O/F frameworks has been synthesized by a solid-state reaction in a closed system. Compared with the lead fluorooxoborate PbB5O8F, BaB5O8F·xH2O exhibits a comparable birefringence and a wider UV transparency window.

Borates are one of the most important classes of functional materials, and several hundreds of artificial borates have been synthesized. The substitution of oxygen by fluorine leads to manifold classes of borates. Fluorooxoborates (also known as fluoroborates), in which the F atoms covalently connect with the B atoms, show additional compositional and structural diversity compared to classic borates. Recently, owing to the large polarizability anisotropy, large HOMO-LUMO gaps, and high hyperpolarizability of the oxyfluoride BOx F4-x building blocks, fluorooxoborates have received unprecedented attention in the search for new ultraviolet (UV) and deep-UV (DUV) nonlinear optical (NLO) materials. Specifically, some compounds have excellent NLO properties that are comparable or superior to KBe2 BO3 F2 , which is the only usable crystal that generates coherent light below 200 nm through a direct second harmonic generation (SHG) process. This Minireview illustrates recent progress on the synthesis, crystal structures, structure-properties relationships and applications of fluorooxoborates. This paper concludes by highlighting the outstanding opportunities offered by NLO fluorooxoborate crystals as an innovative avenue for DUV all solid-state coherent light generation.

Large organic pollutants in wastewater are harmful to human health and environmental ecosystem, and it is of great importance to remove them from waste water. In this report, hierarchical-pore metal-organic frameworks with different mesopore sizes (H-UiO-66-3.8 nm and H-UiO-66-17.3 nm) have been successfully synthesized at reflux condition. The resulting MOFs are characterized by N2 adsorption-desorption analysis and the results show that the samples have hierarchical-pore structures, which indicate the heat reflux method is efficient for the synthesis of H-UiO-66s on liter scale. In order to test the performance of H-UiO-66s for large organic pollutants capture, tetracycline (TC) was taken as an example to perform adsorption experiments. Remarkably, two kinds of H-UiO-66s exhibit significant improvement of adsorptive capacities compared with microporous UiO-66. The adsorption quantity of TC in H-UiO-66-17.3 nm is 666.67 mg·g−1, which is 430% higher than the value in original microporous UiO-66. In addition, the capture ability of H-UiO-66-17.3 nm surpasses various reported adsorbent materials, such as nanocomposite, activated carbon and NH2-MIL-101(Cr). Meanwhile, the H-UiO-66-3.8 nm and H-UiO-66-17.3 nm also show high adsorption capacities for Rhodamine B (RhB) and tannic acid (TA), indicating H-UiO-66s have wide potential application for capture various large organic pollutants. These results show that H-UiO-66s can be successfully synthesized on liter scale under reflux condition and these materials perform excellent adsorption capacities for various organic pollutants, leading the potential application in wastewater treatment.

The three metal iodates Ba(MoO2)2(IO3)4O (1), Ba3[(MoO2)2(IO3)4O(OH)4]·2H2O (2), and Sr[(MoO2)6(IO4)2O4]·H2O (3) have been successfully synthesized by introducing second-order Jahn–Teller distorted Mo6+ cations by a mild hydrothermal method. Single-crystal X-ray diffraction (XRD) was used to determine the structures of the three title compounds. In compound 1, the [Mo2O11]10– dimers connect with the [IO3]− units by sharing oxygen atoms to form two-dimensional (2D) layers that are separated by the Ba2+ cations. For comparison, the [Mo2O11]10– dimers and the [IO3]− units are isolated in compound 2, and they are connected by the [BaO11]20– polyhedra forming a 3D network. For compound 3, the [MoO6]6– polyhedra link with each other by corner and edge sharing to build 2D corrugated layers with tunnels containing isolated [IO4]3– units. The [SrO9]16- polyhedra link the 2D corrugated layers to form a 3D network. The infrared (IR) spectra, the ultraviolet–visible–near-infrared (UV–vis–NIR) diffuse reflectance spec...

If a bucket is to hold more water, its shortest plank must be made longer. This guideline also applies to the exploration of ultraviolet (UV) and deep-UV (DUV) nonlinear optical (NLO) materials that are limited by multiple criteria. Phosphates are one kind of promising candidate for new NLO materials. Unfortunately, the small birefringence, as the shortest plank, severely restricts the phase-matching of second harmonic generation (SHG) in the UV/DUV region. In this work, fluorophosphates are rationally proposed as substitutes for phosphates to break down the limitation of birefringence and simultaneously enhance SHG response and retain wide UV transmittance. The (PO3F)2– and (PO2F2)− groups are confirmed as superior material genomes to achieve the discussed combination properties. Accordingly, (NH4)2PO3F was screened out by density functional theory calculation, and single crystals with centimeter size have been grown. It possesses a powder SHG efficiency of 1 × KH2PO4 (KDP) and is phase-matchable with ou...

The large number and structural beauty of silicates are largely due to the variety of connection mode of SiO4 tetrahedra. SiO6 and SiF6 octahedra are also known and give rise for structural versatility of inorganic silicates. However, to date, the crystal structure of inorganic fluorooxosilicates with oxofluoride SiOx F4-x or SiOx F6-x species are unknown. Now, fluorine was successfully introduced into the silicophosphates, and the first fluorooxosilicophosphate K4 Si3 P2 O7 F12 with an unprecedented SiO2 F4 species was synthesized. The existence of Si-F bonds was verified by comprehensively experimental and theoretical work. Using ab initio and bond valence calculations, the oxofluoride SiOx F6-x species is shown to be stable when oxygen atoms connect to other atoms with strong covalent interactions. This work will contribute to the structural diversity of silicate chemistry by the exploration of the new fluorooxosilicates.

K3 B6 O9 F3 , a first fluorooxoborate containing four different units, that is, [BO3 ]3- , [BO4 ]5- , [BO3 F]4- , and [BO2 F2 ]3- , has been designed and synthesized by two different routes. The unique anionic 2∞ [B6 O9 F3 ]3- layers avoid forming terminal oxygen atoms, which are beneficial to enlarge the band gap. The structure-properties relationship of the title compound is discussed.

Higher hydrocarbons in natural gas must be removed for safe storage, transport, and application of natural gas. Considering C3H8 and CH4 are nonpolar molecules, electrostatic interactions between C3 and MOFs are relatively weak, while they could be sensitive to the van der Waals interactions. Thus, it is an effective method to greatly enhance the separation performance by improving the van der Waals interactions through tuning the pore size of MOFs. Herein, we synthesized a series of isostructural Zr-MOFs with different pore sizes, and the separation performances of these materials for C3/C1 were systematically studied. The results indicate that pore size plays an important role in the C3 storage and C3/C1 separation in MOFs. Specifically, Zr-BPDC with large surface area and pore volume has the highest C3H8 and C3H6 adsorption capacity (159.2 cc/g and 161.5 cc/g at 298 K 1 bar, respectively), while Zr-FUM with the smallest surface area and pore volume has the highest adsorption heat for C3 as well as C3/C...

This paper explored the reason that the amount of methanol consumed is much lower than that of its theoretical value in terms of calorific value in diesel methanol dual fuel (DMDF) combustion by the means of engine bench test and modeling analysis. The results from experiments show that, the DMDF has much higher combustion rate than that of the correspondent diesel (D) mode and the accelerating effect caused by methanol changes with engine load, methanol-air mixture concentration and intake air temperature. At low load condition, the ignition delay caused by methanol is dominated while the accelerating effect is weak. However, this situation just turned upside down at high loads, to bring forth great improvement in isochoric degree. When methanol conducts quickly burning, both the combustion efficiency and the conversion efficiency from heat to work are improved, and the replacement ratio S R becomes much lower than its theoretical value 2.16. In order to reveal the mechanism of high efficiency DMDF at various running conditions, a 3-dimensional CFD model to simulate and analysis the process of methanol burning together with diesel was built. By fixing constant operating parameters and boundary conditions, both the putting off and accelerating effects caused by methanol are enhanced with increasing methanol concentration. The putting off effect weakens with rising air temperature, while the accelerating effect becomes more effective in this process. Hence, the isochoric degree for DMDF deteriorates with rising air temperature at lean methanol mixture but improves as the concentration increases. Finally, a relational graph among isochoric degree, heat release concentration degree, methanol-air mixture concentration and temperature are derived, from which we get the understanding of controllable methanol quick combustion (CMQC) to further improve the DMDF thermal efficiency.

Based on European Steady-state Cycle (ESC) test procedure, an engine test was carried out to meet the demand of Euro V legislation with diesel methanol compound combustion (DMCC) technology on a common-rail, turbocharged, inter-cooling heavy-duty and high pressure exhaust gas recirculation (HP EGR) diesel engine with meeting the requirements of Euro IV legislation. The engine was just modified with DMCC technology and combined with after-treatment device diesel oxidation catalyst coupled with particulate oxidation catalyst (DPOC). The test results show that it can fully meet the demand of Euro V legislation without the help of selected catalyst reduction (SCR). Additionally, the comparative analysis of the dynamic and economic performances between the DMCC Euro V engine and the baseline Euro IV engine was presented in this study. The regulated emissions (included HC, CO, NOX, PM (particulate matter)) and unregulated emissions (included formaldehyde (HCHO) and unburned methanol (CH3OH)) before and after DPOC from DMCC Euro V engine were also investigated. The dynamic performance of DMCC Euro V engine is basically consistent with the baseline Euro IV engine, while there is a slight deterioration in economic performance at certain operation conditions in terms of calorific value. Compared with the baseline engine before DPOC, the DMCC engine causes an increase in HC, CO, HCHO and CH3OH emissions, but the NOX and PM emissions are much better. The DPOC efficiency in the conversion rate of HC, CO, HCHO and CH3OH is over 98% under the whole ESC test procedure, and for PM, the conversion efficiency is only around 21%. However, DPOC has no obvious influence on the conversion of NOX emissions.

Three alkaline metal borates Cs2B7O9(OH)5, K2B4O5(OH)4·H2O, and K2B4O5(OH)4·3.6H2O have been synthesized by a hydrothermal method. They were structurally characterized by single crystal X-ray diffraction. In the three compounds, the B–O anionic groups are all isolated, which are combined through the Cs/K–O polyhedra to form a three-dimensional (3D) network. The cationic framework presents different dimensions in Cs2B7O9(OH)5, K2B4O5(OH)4·H2O and K2B4O5(OH)4·3.6H2O. For Cs2B7O9(OH)5, which has been reported before, we obtained its large-scale crystal and the UV-vis diffuse reflectance spectral data of Cs2B7O9(OH)5 indicate that it has a UV cut-off edge of 209 nm which corresponds to an energy gap of 5.93 eV. Theoretical calculations were carried out to evaluate the band gaps of the title compounds, which illuminate that the replacement of K enlarges the band gap. Besides, the structural discrepancy among Cs2B7O9(OH)5, K2B4O5(OH)4·H2O and K2B4O5(OH)4·3.6H2O is compared to analyze the effect of the cation number on the polymerization degree of the B–O anionic groups. Density functional theory calculations were employed to evaluate the band structures and the density of states suggest that Cs2B7O9(OH)5 and K2B4O5(OH)4·H2O possess wide band gaps of 5.23 and 5.24 eV, respectively. Meanwhile, the large-scale crystal of Cs2B7O9(OH)5 was obtained.

A diesel engine with 6-cylinder, turbocharged intercooling and common rail system was modified to operate on diesel/methanol dual fuel (DMDF). To optimize combustion process at high methanol substitution ratio (MSR) and further decrease exhaust emissions of DMDF engine at low load condition, pilot injection strategy was applied on it and the combustion, regulated and unregulated gaseous emission (included NOx, CO, THC, carbon dioxide (CO 2 ), nitrous oxide (N 2 O), unburned methanol (CH 3 OH), formaldehyde (HCHO), formic acid (HCOOH), 1,3-butadiene (1,3-C 4 H 6 ), benzene (C 6 H 6 ) and toluene (C 7 H 8 )) characteristics were experimentally investigated. Experimental results reveal that the application of pilot injection could improve combustion stability and fuel economy at high MSR, and it can also reduce regulated emissions CO, THC except NOx, and unregulated emissions tested in this study except CO 2 on M0 and M10 mode and toluene on M50 mode when compared with single injection cases. Increase pilot injection quantity and advance pilot injection timing both cause an increase in in-cylinder temperature and pressure before main combustion. The variations of pilot injection quantity and timing have less effect on regulated and unregulated gaseous emissions except NOx on M0 and M10 mode than higher MSR mode. With the rise of pilot quantity and the advance of pilot injection timing, HC and CO emissions decrease gradually but NOx emissions ascend; almost all unregulated emissions tested in this study on M30 mode reduce gradually; but when the MSR continues to rise to 50%, increasing emissions in unburned methanol, 1,3-butadiene and benzene are observed.

The diverse oxyfluoride species and vast number of different topological arrangements lead to fluorooxoborates' structural beauty and richness. Herein, the first mixed alkali/alkaline-earth metal fluorooxoborate Ba

A new barium fluorooxoborate, BaB5O8F·xH2O (x ≈ 0.17), with two interesting independent three-dimensional B-O/F frameworks has been synthesized by a solid-state reaction in a closed system. Compared with the lead fluorooxoborate PbB5O8F, BaB5O8F·xH2O exhibits a comparable birefringence and a wider UV transparency window.

Two mixed halogen borate-carbonates K

Three fluorooxoborates, K0.42Rb2.58B3O3F6 and M3B2PO5F4 (M = K, Cs), were designed and synthesized under the open system. One of the common features is that the title compounds consist of six-membered oxofluoride anions. The oxofluoride anions [B3O3F6]3- and [B2PO5F4]3- display structures similar to the boroxine [B3O6]3-. Anionic group substitution using the [BO2F2]3- and [PO4]3- units can improve the optical property of the [B3O6]3- anion and help to generate a wide transmittance window.

Herein, we present the first lithium difluorophosphate LiPO2F2 exhibiting a unique polytetrahedral microporous architecture. The unique fluorine coordination environments and interlaced [LiO2]3- straight chains give rise to the neutral pore framework with a 10- membered ring channel along the crystallographic c axis. A variety of measurements have been adopted to systemically characterize LiPO2F2. This work contributes to the structural and functional diversity of phosphate chemistry by the exploration of fascinating difluorophosphates.

For ammonia (NH3), a kind of vital pollutant and raw chemical material, it is of great importance to develop materials with high stability and efficient capture performance from dry and humid atmosphere. Herein, a new IL@MOF composite was designed to enhance the NH3 adsorption capacity using the ionic liquids (ILs) and stable metal–organic frameworks (MOFs). The obtained [BOHmim][Zn2Cl5]@MIL-101(Cr) exhibits a record NH3 uptake of 24.12 mmol/g among the reported porous materials at 298 K and 1 bar, more than twice that of MIL-101(Cr) (8.92 mmol/g). More importantly, the composite is stable under the humid NH3 conditions and the excellent NH3 adsorption capacity can be well maintained (23.55 mmol/g) in a 20% NH3 solution (approaching the saturated ammonia solution) steam atmosphere with good regenerability. The mechanism reveals that the metal center and hydroxyl-functionalized alkyl chain of IL confined in the framework of MOF provide multiple adsorption sites and large free volume for NH3 capture. Moreover, the adsorbed water molecules can act as the additional adsorption sites, contributing to the excellent adsorption capacity in humid conditions. This work provides a general way to develop adsorbents for the capture of corrosive gases in combination of the advantages of IL and MOFs.

The methanol fuel used in diesel engine can reduce the emissions effectively, while the performance of engine keeps unchanged or even improved, the study of methanol used in diesel engine is paid more and more attention. Experiments were conducted in a 4-cylinder, turbocharged direct injection diesel engine fueled with diesel/methanol dual fuel (DMDF). In the experiment, methanol was injected into inlet duct by two low-pressure injectors, and directly mixed with intake air before entering the engine. The diesel fuel was directly injected in cylinder. The methanol substitution percent (MSP), intake air temperature and engine speed were changed to investigate the unevenness degree (UED) cylinder-to-cylinder. The experimental results show that the UED of engine increases with the increase of MSP under various engine loads, the COV pp increases with MSP under low engine load, and the COV pp curves vary very little under low MSP under 75% and 100% engine load, but a significantly rise appeared when MSP further increases. The UED gradually increases with the increase of intake air temperature, and it is usually less than 8% when intake air temperatures lower than 80 °C under 40% MSP. It suggests it is helpful to decrease the UED when the intake air temperature is in the range of 35–80 °C as MSP less than 40%. In addition, the difference of pressure between cylinder-to-cylinder decreases with the increase of engine speed, it can be considered raising MSP at high engine speed in order to gain better engine economy.

In this study, port premixed methanol compression ignition combustion was performed on a heavy-duty diesel engine. The effects of methanol to diesel ratio (RMD) and DIT (diesel injection timing) on combustion, performance and emissions were comprehensively investigated. The experimental results demonstrated that RMD and DIT played important roles in combustion and emission control. With the increasing RMD, the ignition delay was prolonged and the combustion duration was shortened. And as DIT retarded, the ignition delay was also prolonged and the combustion duration basically remained unchanged at the beginning, and then followed by a slight decrease. The maximum in-cylinder mean temperature decreased with the retarding DIT and it was largely affected by the combine of RMD and DIT. The brake thermal efficiency remained stable at low RMD, but showed a slight decrease at high RMD. NOX and soot emissions and the RI (ringing intensity) were all decreased as RMD increase, while HC and CO emissions increased significantly. With the retarding DIT, HC emission firstly increased and then decreased, while CO emission always increased. It was more important that the trade-off relationship between NOX and soot was significantly improved with the increasing RMD and almost disappeared at RMD 1.54.

This paper presented the analytical results for the energy balance of a diesel methanol dual-fuel (DMDF) engine. A methanol injection system was fixed on a diesel engine and let the engine to alternate to run in either the pure diesel (D) mode or DMDF mode. Primary application of the thermal balance analysis was to investigate the cause of methanol replacement ratio SR changing with engine loads. Calculations were conducted within the control volume by comparing each of the energy terms. The results show that the reduction in cooling loss in DMDF mode is the dominant factor for low SR at high loads. While, a substantial increase in incomplete combustion loss in DMDF mode is the most important reason for high SR at low loads. Another application of the thermal balance analysis was to research the cooling loss in DMDF mode which implied unique characteristics. Therefore, the changing methanol replacement rate SP experiments were carried out in various engine loads, giving the results that the cooling loss in DMDF mode is always lower than that in D mode, and it goes even lower as SP rises. Finally, the effect of methanol temperature on SR was also investigated from the thermal balance point of view. The results reveal that the incomplete combustion loss decreasing in higher methanol temperature conditions will lead to a certain extent of SR drop. All these results are related to the energy flow distribution within the engine.

To better understand how the intake air temperature and methanol fumigation affect the performance and emissions of diesel engine, a parametric study concerned with methanol mass fraction and intake air temperature was conducted. In this study, methanol port injection was used for preparing homogenous charge for diesel methanol dual fuel operation on a 6-cylinder turbocharged intercooler heavy duty (HD) diesel engine. The testing work was operated at a constant load and constant engine speed of 1500 r/min. The experimental results show that there was a strong coupling between the intake air temperature and the methanol fraction to performance and emissions of the engine. At dual fuel operation mode, decreasing intake air temperature reduced the indicated thermal efficiency and exhaust gas temperature and the trend was more evidently as methanol energy fraction increased. Decreasing of intake air temperature also prolonged the ignition delay, which caused a later combustion phasing and smaller peak cylinder pressure. By the induction of methanol, NO X , NO and smoke emissions decreased markedly, while NO 2 , CO, total hydrocarbon (THC), formaldehyde and methanol emissions increased. However, increasing the intake air temperature would inhibit the NO 2 , THC, CO, formaldehyde and methanol emissions and increase NO, NO X and soot emissions. The effect of intake air temperature and methanol fraction on emissions is more remarkably at a larger methanol fraction (30% or more) and higher intake air temperatures such as 60–70 °C.

Separation of hydrogen isotopes is of great importance to produce highly pure hydrogen isotopes for numerous applications, which is however very difficult because of their almost identical thermodynamic properties. Adsorptive separation is considered as a simple, highly efficient, and cost-effective technique compared to the traditional methods, where the key is the suitable adsorbent. Herein, SIFSIX-3-Zn was screened out from the reported metal–organic frameworks (MOFs), exhibiting high selectivities for a D2/H2 mixture by quantum sieving effect. Advanced cryogenic thermal desorption spectroscopy confirms the calculation results, indicating that the selectivities for a 1:1 D2/H2 mixture at 20 K are larger than the values reported so far; especially, it shows a record value of 53.8 at 25 kPa. This demonstrates that this MOF is a promising candidate for highly effective hydrogen isotope separation.

The three metal iodates Ba(MoO