Zeolites are widely used in many industries. There is still a need to fully understand their intrinsic catalytic nature due to the complexity of the hydroxyl-aluminum moieties.Atomic-scale analysis of local environments for the hydroxyl species is essential for revealing the intrinsic catalytic activity of zeolites and guiding the design of high-performance catalysts. However, many unfavorable factors prohibit the elucidation of their fine structures such as low quantity, meta-stable property, structural similarity, hydrogen-bonding environment, and long-range disordered nature.Recently, a research team led by Prof. HOU Guangjin and Prof. CHEN Kuizhi from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) unraveled the precise structure of complex hydroxyl groups in zeolites with a comprehensive set of self-developed coupling-edited 1H-17O solid-state nuclear magnetic resonance (NMR) methods. The study was published in the Journal of the American Chemical Society and was selected as a supplementary cover.Atomic-scale structure in zeolites revealed by highly sensitive 1H-17O solid-state nuclear magnetic resonance (Image by JI Yi)The 17O solid-state NMR would be a candidate to improve the analytical precision of zeolites if it could overcome the technical difficulties related to the extremely low natural abundance, low gyromagnetic ratio, and quadrupolar nature of 17O isotope. Therefore, the researchers employed a novel 17O-enrichment method and developed a series of 17O-NMR-based spectral editing pulse sequences, allowing them to improve the spectral resolution and address the subtle protonic structures within zeolites.The precise and high-resolution species identification was attributed to comprehensively addressing an often-neglected and undesired NMR interaction, namely, the 2nd-order quadrupolar-dipolar cross-term interaction (2nd-QD interaction), which was indeed helpful in gaining invaluable information on zeolite structures.Besides, researchers quantitatively probed Al···H, O···H proximities within both one-bond and multi-bond ranges, and semi-quantitatively realized the dissociation rates of hydroxyl protons such as Brønsted acid site. They revealed the atomic-scale local environment of the catalytically important Al-OH and Si-OH moieties.The NMR techniques developed in this study might be further applied in providing high-resolution analysis of subtle protonic structures in other circumstances such as metal-oxide surfaces, metal-organic frameworks, and biomaterials."Our study may provide a generic strategy for high-resolution analysis of the subtle protonic structures in zeolites with 17O solid-state NMR," said Prof. HOU.This work was supported by the National Key R&D Program of China, the National Natural Science Foundation of China, the Liaoning Revitalization Talents Program, and the DICP Innovation Foundation.

How mutations impact protein stability and structure dynamics is crucial for understanding the molecular mechanism of the disease and the targeted drug design. However, probing the molecular details of mutation-induced subtle structure dynamics is still challenging.Recently, a research group led by Prof. WANG Fangjun from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) developed a time-resolved native mass spectrometry (TR-nMS) strategy coupled with ultraviolet photodissociation (UVPD) analysis. This strategy can interrogate the mutation-induced subtle alterations in protein stability and structure unfolding dynamics, which provides a new technology for studying mutation-induced pathological mechanisms.This study was published in the Journal of the American Chemical Society on Mar. 20.TR-nMS and 193 nm UVPD for exploring the mutation-induced alterations on protein stability and unfolding dynamics (Image by LUO Pan and LIU Zheyi)The researchers initiated the protein unfolding process by mixing the protein online with formic acid. With native mass spectrometry (nMS) and non-denaturing electrospray ionization (nESI), they monitored the species and relative intensities of acid-initiated protein unfolding intermediates via the unique charge state distributions (CSDs), and they quantitatively characterized the M42T/H114R mutations induced stability alterations of target proteins.In addition, the researchers further employed UVPD and fragment ion mass spectrometry methods to quantitatively compare the dynamic structure and molecular details of the unfolding intermediates of wild-type dihydrofolate reductase (DHFR) and the mutant. The UVPD analysis revealed the special stabilization effect of cofactor nicotinamide adenine dinucleotide phosphate (NADPH) on DHFR structure, and the M42T/H114R mutations could reduce the non-covalent NADPH-DHFR interactions, including residues I41, Q65, V78, D79, I82, and R98, thus promoting a decrease in stability."This work provides a new technique for studying the mutation-induced subtle structure dynamics and pathological mechanisms," said Prof. WANG.

Biomimetic tactile is a fundamental means for intelligent robots to perceive external environmental stimuli.For traditional tactile sensors, direct physical contact with the thermal source was required to obtain the temperature information. However, such contact operating mode had a notable shortcoming: the potential physical damage when processing noxious thermal stimuli.Therefore, it is necessary to develop the non-contact temperature perception function of e-skin for soft robotics and other interactive technologies.Recently, a research team led by Prof. JIANG Peng, Associate Prof. LU Xiaowei, and Prof. BAO Xinhe from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) developed a flexible and wearable long-wave infrared detector, which enabled touchless thermosensation function of electronic skin.This study was published in Advanced Materials on March 8.A flexible wearable photothermoelectric detector enables touchless thermosensation over a broad source temperature range from –50 to 110°C (Image by GUO Xiaohan and LU Xiaowei)Photothermoelectric (PTE) detectors, based on the combination of photothermal and thermoelectric conversions, can realize ultra-broadband photodetection without requiring cooling and external bias. They are particularly suitable for bionic applications involving infrared detection.In this study, the researchers developed a flexible and wearable infrared detector by coupling the Te/CuTe thermoelectric heterostructure and the infrared-absorbing polyimide (PI) substrate. They found that the Te/CuTe thermoelectric heterostructure could reduce the noise equivalent power by improving the power factor. Moreover, they realized efficient PTE coupling by suppressing the optical reflection loss and aligning the destructive interference position with the absorption peak of the PI substrate, which improved the performance of PTE detector.Besides, the researchers investigated the performance of PTE detector. They proved that when the temperature of the thermal source varied from –50 to 110°C, the fabricated flexible PTE detector, in the contactless mode, exhibited higher sensitivity than the commercial rigid thermopile. With this wearable infrared detector, they established a temperature pre-warning system for a soft robotic gripper that could distinguish the noxious thermal stimulus in a dynamic and contactless manner."This work provides a feasible strategy to integrate the infrared detection technique into the sensory modality of electronic skin, exhibiting great potential for smart robotics, artificial intelligence, and augmented reality," said Prof. JIANGThe above work was supported by the National Natural Science Foundation of China, the National Key R&D Program of China, the Natural Science Foundation of Liaoning Province, the CAS Interdisciplinary Innovation Team, and DICP.

Pyrogenic carbon is widely produced during the incomplete combustion of biomass and fossil fuels on land. About one-third of pyrogenic carbon is exported to the ocean by rivers, and thereinto, the refractory fraction becomes the source of oceanic black carbon that can provide a long-term sink for atmospheric CO2.The chemical signature of black carbon in the oceans differs from pyrogenic carbon in rivers. Specifically, unknown degradations that account for the losses of pyrogenic carbon or carbon-13 enrichment of pyrogenic carbon should exist as terrigenous refractory pyrogenic carbon transits coastal waters. Unveiling this enigma is helpful in verifying the role of oceanic pyrogenic carbon in buffering climate change, but it still needs to be clarified.Now, Prof. WANG Feng's group from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) and their collaborators have identified a degradation process that may be a significant contributor to the deposition of 13C-enriched pyrogenic carbon in coastal sediments. Their findings were published in the Journal of the American Chemical Society on Mar. 18.The coastal ocean surface harbors abundant wave energy. Wave energy dissipation through wave breaking is a prominent source of sprayed water microdroplets on Earth. Water microdroplets possess a high electric field at the interface of microdroplets, which is sufficient to pull electrons out of hydroxide ions.Researchers found that seawater microdroplets can couple this interfacial electron transfer pathway with that caused by contact electrification at microdroplet water-carbon interfaces to accelerate refractory pyrogenic carbon degradation. This electrochemical degradation process can lead to a large fractionation of stable carbon isotopes and account for the deposition of refractory pyrogenic carbon.Besides, the researchers proposed a hypothesis that the resuspension of such deposited refractory pyrogenic carbon could act as a source of 13C-enriched black carbon in the open ocean. They indicated that with intensifying wave energy due to anthropogenic global warming, the chemical effect of seawater microdroplets in the marine carbon cycle requires more attention.

Solar thermal fuels (STFs) can convert solar energy into chemical energy, which can be stored for a long time and released as thermal energy through specific triggers when needed.STFs are promising for solar thermal utilization since they can address the problems of solar energy's intermittent availability and weather/geographic dependency. However, the current research on STFs mainly focuses on molecular-based materials with different molecular conformations showing energy differences, which pose challenges in practical large-scale applications.Recently, a research group led by Prof. SHI Quan from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has proposed an erythritol (ERY)-based spatiotemporal phase change material (STPCMs) that can serve as a new type of STFs, and have the potential for large-scale applications.This study was published in Angewandte Chemie International Edition on Feb. 20.The researchers demonstrated that the developed erythritol-polyacrylamide-polydopamine (ERY-PAM-PDA) composite STPCMs had the spatiotemporal utilization of thermal energy and photothermal conversion ability.Schematic diagram of the composite STPCM (Image by ZHANG Shihui)The researchers found that after introducing a photothermal conversion unit, the composite STPCM exhibited good photothermal conversion efficiency and realized the conversion and storage of solar energy into thermal energy. In addition, the composite STPCM could store thermal energy for more than a month at room temperature and then controllably release the stored latent heat via thermal induction or mechanical triggering. The cold crystallization enthalpy could reach 224.9 J/g, and the released latent heat could heat the system from room temperature (25 °C) to 91 °C.The composite STPCM reported in this work is a promising alternative to molecular-based STFs. It exhibited spatiotemporal utilization capabilities for thermal energy and photothermal conversion ability in the visible light region. Moreover, it had simple preparation methods, used cheap and readily available raw materials, and was applicable to large-scale production."This work provides a new direction for the application of STPCMs and the development of solar thermal utilization technology," said Prof. SHI.The above work was supported by the National Key Research and Development Program of China and the National Nature Science Foundation of China.

Direct conversion of CH4 and O2 to value-added chemicals is important for natural gas industries. However, challenges remain due to the difficulty of O2 activation in forming active oxygen species for CH4 activation under mild conditions.Recently, a research group led by Prof. DENG Dehui, Assoc. Prof. CUI xiaoju and YU Liang from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) realized the electrochemical conversion of CH4 by O2 to HCOOH at room temperature.This study was published in the Journal of the American Chemical Society and was selected as a supplementary cover.Schematic diagram of CH4 conversion to HCOOH by the hetero-homogeneous coupling electro-catalytic process (Image by Dehui Deng)The researchers developed a high-pressure electro-Fenton strategy to establish a hetero-homogeneous process for electro-catalytic conversion of CH4 by O2 at room temperature. They revealed that CH4 was efficiently activated by ·OH, which was produced via a heterogeneous electroreduction of O2 to H2O2 on the Ag foil cathode, followed by a homogeneous Fe2+-facilitated H2O2 decomposition.Besides, the researchers found that the elevated pressure not only improved the productivity of H2O2 from O2 electro-reduction but also boosted the reaction collision probability between CH4 and active ·OH in-situ generated from Fe2+-facilitated decomposition of H2O2.Compared with the traditional electro-catalytic CH4 conversion process with high overpotential (>0.9 V) and low Faradaic efficiency (< 60%), the high-pressure electro-Fenton process achieved an HCOOH Faradaic efficiency of 81.4% with an ultra-low cathodic overpotential of 0.38 V. The HCOOH productivity was 11.5 mmol h-1 gFe-1, which was 220 times that of ambient pressure."This work provides a new way for energy-efficient and sustainable conversion of CH4 by directly using O2 under mild conditions," said Prof. DENG.This work was supported by the National Key R&D Program of China, the National Natural Science Foundation of China, the Strategic Priority Research Program of CAS, and the Fundamental Research Funds for the Central Universities.