Sinopec Research Institute of Petroleum Processing

Abstract Dual‐atom site catalysts (DACs) have emerged as a new frontier in heterogeneous catalysis because the synergistic effect between adjacent metal atoms can promote their catalytic activity while maintaining the advantages of single‐atom site catalysts (SACs), like 100 % atomic utilization efficiency and excellent selectivity. Herein, a supported Pd 2 DAC was synthesized and used for electrochemical CO 2 reduction reaction (CO 2 RR) for the first time. The as‐obtained Pd 2 DAC exhibited superior CO 2 RR catalytic performance with 98.2 % CO faradic efficiency at −0.85 V vs. RHE, far exceeding that of Pd 1 SAC, and coupled with long‐term stability. The density functional theory (DFT) calculations revealed that the intrinsic reason for the superior activity of Pd 2 DAC toward CO 2 RR was the electron transfer between Pd atoms at the dimeric Pd sites. Thus, Pd 2 DAC possessed moderate adsorption strength of CO*, which was beneficial for CO production in CO 2 RR.

Abstract Ruthenium dioxide is presently the most active catalyst for the oxygen evolution reaction (OER) in acidic media but suffers from severe Ru dissolution resulting from the high covalency of Ru-O bonds triggering lattice oxygen oxidation. Here, we report an interstitial silicon-doping strategy to stabilize the highly active Ru sites of RuO 2 while suppressing lattice oxygen oxidation. The representative Si-RuO 2 −0.1 catalyst exhibits high activity and stability in acid with a negligible degradation rate of ~52 μV h −1 in an 800 h test and an overpotential of 226 mV at 10 mA cm −2 . Differential electrochemical mass spectrometry (DEMS) results demonstrate that the lattice oxygen oxidation pathway of the Si-RuO 2 −0.1 was suppressed by ∼95% compared to that of commercial RuO 2 , which is highly responsible for the extraordinary stability. This work supplied a unique mentality to guide future developments on Ru-based oxide catalysts’ stability in an acidic environment.

), which is much higher than those of other materials reported so far, including silver-doped adsorbents, inorganic porous materials, metal-organic frameworks, porous organic frameworks, and other COFs. Furthermore, a combined theoretical and experimental study, including DFT calculations, electron paramagnetic resonance spectroscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy, reveals the strong chemical interaction between iodine and the frameworks of the materials. Our study thus opens an avenue to construct functional COFs for a critical environment-related application.

Ion selective separators with the capability of conducting lithium ion and blocking polysulfides are critical and highly desired for high-performance lithium–sulfur (Li–S) batteries. Herein, we fabricate an ion selective film of covalent organic framework (denoted as TpPa-SO3Li) onto the commercial Celgard separator. The aligned nanochannels and continuous negatively charged sites in the TpPa-SO3Li layer can effectively facilitate the lithium ion conduction and meanwhile significantly suppress the diffusion of polysulfides via the electrostatic interaction. Consequently, the TpPa-SO3Li layer exhibits excellent ion selectivity with an extremely high lithium ion transference number of 0.88. When using this novel functional layer, the Li–S batteries with a high sulfur loading of 5.4 mg cm–2 can acquire a high initial capacity of 822.9 mA h g–1 and high retention rate of 78% after 100 cycles at 0.2 C. This work provides new insights into developing high-performance Li–S batteries via ion selective separator strategy.

Abstract Aqueous zinc ion batteries (ZIBs) have been extensively investigated as a next‐generation energy storage system due to their high safety and low cost. However, the critical issues of irregular dendrite growth and intricate side reactions severely restrict the further industrialization of ZIBs. Here, a strategy to fabricate a semi‐immobilized ionic liquid interface layer is proposed to protect the Zn anode over a wide temperature range from −35 to 60 °C. The immobilized SiO 2 @cation can form high conjugate racks that can regulate the Zn 2+ concentration gradient and self‐polarizing electric field to guarantee uniform nucleation and planar deposition; the free anions of the ILs can weaken the hydrogen bonds of the water to promote rapid Zn 2+ desolvation and accelerate ion‐transport kinetics simultaneously. Because of these unique advantages, the cycling performance of the symmetric Zn batteries is greatly enhanced, evidenced by a cycling life of 1800 h at 20 mA cm −2 , and a cycle lifespan of 2000 h under a wide temperature window from −35 to 60 °C. The efficiency of this semi‐immobilizing strategy is well demonstrated in various full cells including pouch cells, showing high performance at large current (20 A g −1 ) and wide temperatures with extra‐long cycles up to 80 000 cycles.

Abstract As a traditional method of ammonia (NH 3 ) synthesis, Haber–Bosch method expends a vast amount of energy. An alternative route for NH 3 synthesis is proposed from nitrate (NO 3 − ) via electrocatalysis. However, the structure–activity relationship remains challenging and requires in‐depth research both experimentally and theoretically. Here an N‐coordinated Cu–Ni dual‐single‐atom catalyst anchored in N‐doped carbon (Cu/Ni–NC) is reported, which has competitive activity with a maximal NH 3 Faradaic efficiency of 97.28%. Detailed characterizations demonstrate that the high activity of Cu/Ni–NC mainly comes from the contribution of Cu–Ni dual active sites. That is, (1) the electron transfer (Ni → Cu) reveals the strong electron interaction of Cu–Ni dual‐single‐atom; (2) the strong hybridizations of Cu 3d—and Ni 3d—O 2p orbitals of NO 3 − can accelerate electron transfer from Cu–Ni dual‐site to NO 3 − ; (3) Cu/Ni–NC can effectively decrease the rate‐limiting step barriers, suppress N–N coupling for N 2 O and N 2 formation and hydrogen production.

Abstract Surface segregation constitutes an efficient approach to enhance the alkaline hydrogen evolution reaction (HER) activity of bimetallic Pt x Ni y nanoalloys. Herein, a new strategy is proposed by utilizing the small gas molecule of H 2 as the structure directing agent (SDA) to in situ induce Pt surface segregations over a series of PtNi 5 ‐ n samples with extremely low Pt doping (Pt/Ni = 0.2). Impressively, the sample of PtNi 5 ‐0.3 synthesized under 0.3 MPa H 2 delivers an extremely low overpotential of 26.8 mV (−10 mA cm −2 ) and Tafel slope of 19.2 mV dec −1 , which is superior to most of the previously reported Pt x Ni y electrocatalysts. This is substantially related to the strong H 2 in situ inducing effect to generate Pt‐rich@Ni‐rich core‐shell nanostructure of PtNi 5 ‐0.3 with an ultrahigh Pt surface content of 46%. The specific mechanistic effects of H 2 during the PtNi 5 ‐ n synthesis process are well illustrated based on the combined experimental and theoretical studies. The density functional theory mechanism simulations further unravel that the evolved active site of PtNi 5 ‐ n can efficiently reduce the reaction Gibbs free energies; especially for the scenario of PtNi 5 ‐0.3, the downward‐shifted d band center of the Pt active site significantly reduces the PtH bond strength, eventually resulting in the lowest absolute value of Δ G H .

Conversion of plastic wastes to valuable carbon resources without using noble metal catalysts or external hydrogen remains a challenging task. Here we report a layered self-pillared zeolite that enables the conversion of polyethylene to gasoline with a remarkable selectivity of 99% and yields of >80% in 4 h at 240 °C. The liquid product is primarily composed of branched alkanes (selectivity of 72%), affording a high research octane number of 88.0 that is comparable to commercial gasoline (86.6). In situ inelastic neutron scattering, small-angle neutron scattering, solid-state nuclear magnetic resonance, X-ray absorption spectroscopy and isotope-labelling experiments reveal that the activation of polyethylene is promoted by the open framework tri-coordinated Al sites of the zeolite, followed by β-scission and isomerization on Brönsted acids sites, accompanied by hydride transfer over open framework tri-coordinated Al sites through a self-supplied hydrogen pathway to yield selectivity to branched alkanes. This study shows the potential of layered zeolite materials in enabling the upcycling of plastic wastes.

Abstract MXenes are a family of two‐dimensional (2D) layered transition metal carbides/nitrides that show promising potential for energy storage applications due to their high‐specific surface areas, excellent electron conductivity, good hydrophilicity, and tunable terminations. Among various types of MXenes, Ti 3 C 2 T x is the most widely studied for use in capacitive energy storage applications, especially in supercapacitors (SCs). However, the stacking and oxidation of MXene sheets inevitably lead to a significant loss of electrochemically active sites. To overcome such challenges, carbon materials are frequently incorporated into MXenes to enhance their electrochemical properties. This review introduces the common strategies used for synthesizing Ti 3 C 2 T x , followed by a comprehensive overview of recent developments in Ti 3 C 2 T x /carbon composites as electrode materials for SCs. Ti 3 C 2 T x /carbon composites are categorized based on the dimensions of carbons, including 0D carbon dots, 1D carbon nanotubes and fibers, 2D graphene, and 3D carbon materials (activated carbon, polymer‐derived carbon, etc.). Finally, this review also provides a perspective on developing novel MXenes/carbon composites as electrodes for application in SCs.

The design of efficient catalysts that synergistically promote *H2O decomposition, H2 formation, and desorption is critical to accelerate hydrogen evolution reaction (HER) kinetics but remains a significant challenge. Herein, we design an efficient catalyst of Pt/FeOOH@NiFe LDHs with Pt single-atom and cluster distribution induced by amorphous FeOOH. The Pt/FeOOH@NiFe LDHs with a low Pt content of 2 wt % exhibit ultralow HER overpotentials of 20 and 85 mV in alkaline media (5 and 40 mV in acidic media) to achieve the current densities of 10 and 100 mA cm–2. The overpotentials of specific activity normalized by the electrochemically active surfaces (ECSA) are 100 mV@0.2 mA cmECSA–2 and 140 mV@0.4 mA cmECSA–2. The Tafel slope is 51 mV dec–1, and the HER process follows the Volmer-Hyrovsky mechanism. Moreover, the overall water splitting requires only low voltages of 1.46 V@10 mA cm–2 and 1.61 V@100 mA cm–2, which are better than most reported catalysts. Experimental and theoretical studies show that the amorphous FeOOH can induce the formation of Pt single-atom and cluster with electron redistribution, and the formed Pt single-atom and cluster/FeOOH synergistic active sites exhibit superior HER performance. The amorphous FeOOH in Pt/FeOOH@NiFe LDHs facilitates the adsorption and activation of H2O, and the Pt single-atom and cluster play a key role in the formation and desorption of H2, synergistically accelerating the HER kinetics.

The effects of Ru on the V2O5–WO3/TiO2 catalyst were studied in NOx and chlorobenzene (CB) simultaneous controls in terms of promoting the C–Cl cleavage and decreasing polychlorinated species. Herein, we synthesized Ru-modified vanadia-based catalysts, which demonstrated stable NOx and CB conversions with high selectivity to N2, CO2, and HCl. The newly formed V–O–Ru chains on the surface strengthened the electron capability and narrowed down the band gap of vanadium, which weakened the Lewis acid sites to avoid the generation of polychlorinated species via electrophilic reactions. The formation of oxygen vacancies on Ru–O–Ti was considerably enhanced compared with that on V = O, V–O–V, and V–O–Ti, leading to the acceleration in the ring opening of benzoates, whereas the selective catalytic reduction (SCR) performance below 325 °C remained the same. Ru modification lowered the energy barriers of the C–Cl cleavage and elevated the energy barriers of CB dehydrogenation and chlorination, which are critical steps in CB oxidation and byproduct formation, respectively.

The unsuitable disposal of plastic wastes has caused serious environmental pollution, and finding a green manner to address this problem has aroused wide concern. Plastic wastes, especially polyolefin wastes, are rich in carbon and hydrogen, and chemical recycling shows distinct advantages in their conversion into olefins and realizes a closed-loop cycling of plastic wastes. Plastic wastes should be labeled before disposal. The necessity for, and methods of, pretreatment are introduced in this paper and the whole recycling process of polyolefin wastes is also summarized. As the core technology pyrolysis, including thermal, catalytic and solvolysis processes, is introduced in detail due to its potential for future development. We also briefly describe the feasible strategies of pyrolytic oil refining and life cycle assessment of the chemical recycling process. In addition, suggestions and perspectives concerning the industrial improvement of polyolefin chemical recycling are proposed.

Microalgae have been currently recognized as one group of the most potential feedstocks for biodiesel production due to high productivity potential, efficient biosynthesis of lipids and less competition with food production. Moreover, utilization of microalgae with environmental purposes (CO2 fixation, NOX and wastewater treatment) and biorefinery have been reported. However, there are still challenges that need to be addressed to ensure stable large-scale production with positive net energy balance. This review gives an overview of the current status of the application of microalgae in biodiesel production and environmental protection. The practical problems not only facing the microalgae biodiesel production but also associated with microalgae application for environmental pollution control, in particular biological fixation of greenhouse gas (CO2 and NOX) and wastewater treatment are described in detail. Notably, the synergistic combination of various applications (e.g. food, medicine, wastewater treatment and flue gas treatment) with biodiesel production could enhance the sustainability and economics of the algal biodiesel production system.

catalysts (impregnation, precipitation, and other emerging methods), as well as the metal-support interactions (MSIs), are revisited. Moreover, Some promising applications have been chosen as representative reactions in fine chemicals, environmental purification, and sustainable development fields to highlight the universal functionality of the alumina-supported Pd-based catalysts. The role of the Pd species, alumina support, promoters, and metal-support interactions in the enhancement of catalytic performance are also discussed. Finally, some challenges and upcoming opportunities in the academic and industrial application of the alumina and its supported Pd-based are presented and put forward.

Abstract Li‐rich Mn‐based oxides (LRMOs) are promising cathode materials for next‐generation lithium‐ion batteries (LIBs) with high specific energy (≈900 Wh kg −1 ) because of anionic redox contribution. However, LRMOs suffer from issues such as irreversible release of lattice oxygen, transition metal (TM) dissolution, and parasitic cathode–electrolyte reactions. Herein, a facile, scalable route to build homogenous and ultrathin Li 2 TiO 3 (LTO) coating layer on the primary particles of LRMO through molten salt (LiCl) assisted solid–liquid reaction between TiO 2 and Li 1.08 Mn 0.54 Co 0.13 Ni 0.13 O 2 is reported. The prepared LTO‐coated Li 1.08 Mn 0.54 Co 0.13 Ni 0.13 O 2 (LTO@LRMO) exhibits 99.7% capacity retention and 95.3% voltage retention over 125 cycles at 0.2 C, significantly outperforming uncoated LRMO. Combined characterizations of differential electrochemical mass spectrometry, in situ X‐ray diffraction, and ex situ X‐ray photoelectron spectroscopy evidence significantly suppressed oxygen release, phase transition, and interfacial reactions. Further analysis of cycled electrodes reveals that the LTO coating layer inhibits TM dissolution and prevents the lithium anode from TM crossover effect. This study expands the primary particle coating strategy to upgrade LRMO cathode materials for advanced LIBs.

Proton exchange membrane fuel cell (PEMFC) is one of the most promising energy conversion devices with high efficiency and zero emission. However, oxygen reduction reaction (ORR) at the cathode is still the dominant limiting factor for the practical development of PEMFC due to its sluggish kinetics and the vulnerability of ORR catalysts under harsh operating conditions. Thus, the development of high-performance ORR catalysts is essential and requires a better understanding of the underlying ORR mechanism and the failure mechanisms of ORR catalysts with in situ characterization techniques. This review starts with the introduction of in situ techniques that have been used in the research of the ORR processes, including the principle of the techniques, the design of the in situ cells, and the application of the techniques. Then the in situ studies of the ORR mechanism as well as the failure mechanisms of ORR catalysts in terms of Pt nanoparticle degradation, Pt oxidation, and poisoning by air contaminants are elaborated. Furthermore, the development of high-performance ORR catalysts with high activity, anti-oxidation ability, and toxic-resistance guided by the aforementioned mechanisms and other in situ studies are outlined. Finally, the prospects and challenges for in situ studies of ORR in the future are proposed.

Abstract Zinc metal is a promising choice as a high‐capacity and cost‐effective anode for aqueous zinc‐based batteries. However, it faces challenges related to low cycling stability and poor reversibility due to parasitic reactions and the growth of zinc dendrites. In this study, a solution is proposed by introducing a conductive Ti 4 O 7 layer on the zinc anode to enhance electrode stability. The Ti 4 O 7 layer serves a dual purpose, effectively preventing spontaneous corrosion of the zinc anode in the electrolyte, thereby inhibiting the hydrogen evolution reaction and the generation of byproducts. Simultaneously, it promotes Zn nucleation and ensures a uniform electric field distribution, resulting in homogeneous Zn plating and stripping compared to using a bare zinc anode. Consequently, the Ti 4 O 7 ‐coated Zn anode experiences a significant reduction in over‐potential, demonstrating long‐term stability and dendrite‐free behavior. This outcome ensures low polarization potential and high cycling stability in zinc‐ion batteries. The work underscores the potential of conductive oxides in the development of stable metal electrodes.

We previously showed that both the linear photosynthetic electron transportation rate and the respiration rate dropped significantly during N starvation-induced neutral lipid accumulation in an oil-producing microalga, Chlorella sorokiniana, and proposed a possible role for cyclic electron flow (CEF) in ATP supply. In this study, we further exploited this hypothesis in both Chlorella sorokiniana C3 and the model green alga Chlamydomonas. We found that both the rate of CEF around photosystem I and the activity of thylakoid membrane-located ATP synthetase increased significantly during N starvation to drive ATP production. Furthermore, we demonstrated that the Chlamydomonas mutant pgrl1, which is deficient in PGRL1-mediated CEF, accumulated less neutral lipids and had reduced rates of CEF under N starvation. Further analysis revealed that Ca(2+) signaling regulates N starvation-induced neutral lipid biosynthesis in Chlamydomonas by increasing calmodulin activity and boosting the expression of the calcium sensor protein that regulates Pgrl1-mediated CEF. Thus, Ca(2+)-regulated CEF supplies ATP for N starvation-induced lipid biosynthesis in green alga. The increased CEF may re-equilibrate the ATP/NADPH balance and recycle excess light energy in photosystems to prevent photooxidative damage, suggesting Ca(2+)-regulated CEF also played a key role in protecting and sustaining photosystems.

The synergistic effects of mixed-metal MOFs provide a promising platform to overcome the limitations of traditional monometallic MOFs and achieve superior performance, which are still in their infancy. Mixed-rare earth-based metal-organic frameworks (MRE MOFs) have emerged as a new class of mixed-metal MOFs and attracted significant attention due to the high and variable coordination numbers of rare-earth metal clusters, intriguing architectural structure, and distinguishing functional properties. Despite plenty of factors influencing the preparation of MRE MOFs, it is also a challenge to precisely characterize the states of mixed metals. Particularly, the MRE MOFs with multi-valent rare earth metal nodes are more sophisticated than mixed transition metal MOFs. Multi-scale computational calculation serves as a tool for in-depth interpretation and analysis of the MRE MOFs at the electronic level. In almost every case, several experimental techniques need to be wisely chosen to unambiguously characterize mixed-metal MOFs. In this review, we summarize the recent and important progress in the preparation method, characterization techniques of MRE MOFs prepared by mixing transition and rare-earth metals or mixing multi-rare-earth metals, and their applications in catalysis, adsorption decontamination and luminescence. Special emphasis is placed on the effects of different metals on their structure and properties. Finally, we also present a short conclusion and future research directions for MRE MOFs.

Abstract Aiming at the construction of novel stimuli‐responsive fluorescent system with precisely tunable emissions, the typical 9,14‐diphenyl‐9,14‐dihydrodibenzo[a, c]phenazine (DPAC) luminogen with attractive vibration‐induced emission (VIE) behavior has been introduced into [2]rotaxane as a stopper. Taking advantage of their unique dual stimuli‐responsiveness towards solvent and anion, the resultant [2]rotaxanes reveal both tunable VIE and switchable circularly polarized luminescence (CPL). Attributed to the formation of mechanical bonds, DPAC‐functionalized [2]rotaxanes display interesting VIE behaviors including white‐light emission upon the addition of viscous solvent, as evaluated in detail by femtosecond transient absorption (TA) spectra. In addition, ascribed to the regulation of chirality information transmission through anion‐induced motions of chiral wheel, the resolved chiral [2]rotaxanes reveal unique switchable CPL upon the addition of anion, leading to significant increase in the dissymmetry factors ( g lum ) values with excellent reversibility. Interestingly, upon doping the chiral [2]rotaxanes in stretchable polymer, the blend films reveal remarkable emission change from white light to light blue with significant 6.5‐fold increase in g lum values up to −0.035 under external tensile stresses. This work provides not only a new design strategy for developing molecular systems with fluorescent tunability but also a novel platform for the construction of smart chiral luminescent materials for practical use.