Understanding the atomic-scale structural dynamics of phase transformations is crucial for developing materials and tailoring their properties. However, many materials are obtained as polycrystalline powders with large unit cells and/or complex structures, making it challenging to investigate detailed structural changes using conventional X-ray diffraction techniques. Here we employ time-resolved three-dimensional electron diffraction to reveal the topotactic reactions and transformations that convert the extra-large-pore silicate zeolite ECNU-45 into ECNU-46. ECNU-45 features three-dimensional interconnecting 24 × 10 × 10-ring channels, while ECNU-46 consists of one-dimensional 24-ring channels connected to 10-ring pockets. ECNU-45 and ECNU-46 are both examples of pure silicate zeolites with pore openings larger than 22-ring. Our findings indicate changes at six distinct tetrahedral silicon sites, involving atom displacement, addition and removal of framework atoms through bond breakage and formation. This work presents the synthesis of zeolites and also provides atomic-level insights into the dynamic processes of topotactic reactions. Our results have implications for advancing materials engineering and understanding complex solid-state reactions at an atomic scale. (Figure presented.)

Three-dimensional electron diffraction (3D ED) has emerged as a powerful tool for solving the structures of small crystals down to nanometre-scale sizes. Despite advancements in automating data acquisition for 3D ED, the subsequent data processing and structure solution have largely relied on human intervention and have been mostly conducted offline. This reliance on expertise in electron crystallography and the lack of real-time feedback on data quality and structural information have limited the broader adoption of 3D ED. Here, we introduce Instamatic-solve, a fully automated, real-time structure solution pipeline for 3D ED deployed on a JEOL JEM 2100 transmission electron microscope. Instamatic-solve streamlines the entire process by automating the subsequent data processing and structure solution, providing real-time assessments of data quality and structural information. Moreover, the pipeline can handle offline 3D ED data acquired from various transmission electron microscope platforms. Using Instamatic-solve, we have successfully solved the crystal structures of diverse materials, including seven inorganic zeolites, two inorganic–organic hybrids and four organic molecules (including pharmaceuticals), all within 2 min. Instamatic-solve mimics the typical manual structure solution process, and its outcomes depend heavily on data quality. Our results indicate that a routine and reliable structure solution is achievable in most cases, provided that the data meet critical quality criteria, namely completeness ≥50% and resolution better than 1.0 Å. By enabling efficient, automated and real-time structure solution for crystalline materials, Instamatic-solve spans various scientific disciplines.

The corrugated <110> oriented layered metal halide perovskites (MHP) are gaining increased attention for a variety of properties including intrinsic white light emission. One prototypical candidate is 1-(3-aminopropyl)imidazole lead bromide, which was reported to crystallize as the <110> oriented perovskite (API)PbBr4 [API = 1-(3-aminopropyl)imidazole]. This work shows that under similar reaction conditions, the same components can instead form (API)2Pb3Br10, which has a “perovskitoid” structure. (API)2Pb3Br10 exhibits a reversible phase transition between 60 and −20 °C from a polar space group I2 to a centrosymmetric space group (Formula presented). The structures and properties of both phases have been characterized by single-crystal and powder X-ray diffraction (XRD) and solid-state nuclear magnetic resonance (ssNMR) accompanied by variable-temperature optical absorption and photoluminescence. In addition, a thermal decomposition of (API)PbBr4 into (API)2Pb3Br10 has been observed between 250 and 300 °C.

The DIALS package provides a set of tools for crystallographic data processing. The open-source nature of the project, and a flexible inter­face in which individual command-line pro­grams each have a dedicated job, have enabled the adaptation of DIALS to a wide range of experiment types, including electron diffraction. Here we present detailed instructions for the use of DIALS to process chemical crystallography diffraction data from con­tin­u­ous rotation electron diffraction experiments. We demonstrate processing and structure solution from three different samples from three different instruments, including two commercial instruments dedicated to electron diffraction. Each instrument has a pixel array detector, allowing low-noise data to be obtained, resulting in high quality structures. Various new features were added to DIALS to simplify the workflow for these use cases. These are described in detail, along with useful pro­gram options for electron diffraction work.

In this work, we introduce a modified dip-and-pull electrochemical X-ray photoelectron spectroscopy (ECXPS) approach that offers new mechanistic insight into the alkaline carbon monoxide reduction reaction (CORR) over a Cu(111) single crystal surface. We tackle two major unresolved questions in the CORR mechanism that persist in the literature. Firstly, we address the mechanism for methane formation on Cu(111) and show that the mechanism likely proceeds via atomic carbon, which subsequently couples, leading to the accumulation of amorphous carbon on the surface. Secondly, we provide insight into whether the mechanism for acetate formation occurs entirely on the surface or partially within the solution phase, showing that acetate is present on the surface, indicating a surface-based reaction. These insights into surface-based mechanisms provide a handle for designing future catalysts that can efficiently target the binding of specific intermediates. Furthermore, we expect that our modified approach to dip-and-pull ECXPS – in which we have changed the electrode geometry, the method of introducing the reactant gas and used hard x-rays – will significantly expand the technique's applicability, enabling studies of the CO(2)RR and beyond.

We present serial electron diffraction with tilt (t-SerialED), a method for fast autonomous phase and structural analysis of beam-sensitive, nano-sized polycrystalline materials. Unlike traditional workflows collecting datasets crystal by crystal, t-SerialED acquires datasets using a batch-by-batch approach, which speeds up the data acquisition. t-SerialED combines robust indexing from 3D reciprocal space with still-shot integration and merging methods from serial crystallography. t-SerialED enables high-throughput analysis of beam-sensitive, multi-phase mixtures across a wide range of materials, from nanoporous frameworks to pharmaceutical compounds. By resolving key challenges in serial crystallography such as indexing and preferred orientation, this method enables precise structure determination, including the visualization of guest molecules and non-covalent interactions like hydrogen bonding and proton charge transfer. Demonstrated on a range of samples from nanoporous materials to pharmaceuticals, t-SerialED expands the capabilities of serial chemical crystallography from single-phase to complex multi-phase systems. It can become a complementary method to traditional crystallography methods, offering a robust solution for routine quantitative phase analysis and structure determination.

Understanding the structure of an active pharmaceutical ingredient is essential for gaining insights into its physicochemical properties. Sodium valproate, one of the most effective antiepileptic drugs, was first approved for medical use in 1967. However, the structure of its anhydrous form has remained unresolved. This is because it was difficult to grow crystals of sufficient size for single-crystal X-ray diffraction (SCXRD). Although 3D electron diffraction (3D ED) can be used for studying crystals that are too small for SCXRD, the crystals of anhydrous sodium valproate are extremely sensitive to both humidity and electron beams. They degrade quickly both in air and under an electron beam at room temperature. In this study, we developed a glovebox-assisted cryo-transfer workflow for the preparation of EM grids in a protected atmosphere to overcome the current challenges for studying air- and beam-sensitive samples using 3D ED. Using this technique, we successfully determined the structure of anhydrous sodium valproate, revealing the formation of Na-valproate polyhedral chains. Our results provide a robust framework for the 3D ED analysis of air-sensitive crystals, greatly enhancing its utility across various scientific disciplines.

Zeolites are crystalline microporous materials constructed by corner-sharing tetrahedra (SiO₄ and AlO₄), with many industrial applications as ion exchangers, adsorbents and heterogeneous catalysts. However, the presence of micropores impedes the use of zeolites in areas dealing with bulky substrates. Introducing extrinsic mesopores, that is, intercrystal/intracrystal mesopores, in zeolites is a solution to overcome the diffusion barrier. Still, those extrinsic mesopores are generally disordered and non-uniform; moreover, acidity and crystallinity are always, to some extent, impaired. Thus, synthesizing thermally stable zeolites with intrinsic mesopores that are of uniform size and crystallographically connected with micropores, denoted here as intrinsic mesoporous zeolite, is highly desired but still not achieved. Here we report ZMQ-1 (Zeolitic Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, no. 1), an aluminosilicate zeolite with an intersecting intrinsic meso-microporous channel system delimited by 28 × 10 × 10-rings, in which the 28-ring has a free diameter of 22.76 Å × 11.83 Å, which reaches the mesopore domain. ZMQ-1 has high thermal and hydrothermal stability with tunable framework Si/Al molar ratios. ZMQ-1 is the first aluminosilicate zeolite with an intrinsic meso-microporous channel system. The Brønsted acidity of ZMQ-1 imparts high activity and unique selectivity in the catalytic cracking of heavy oil. The position of the organic structure-directing agent (OSDA) used for ZMQ-1 synthesis was determined from three-dimensional electron diffraction (3D ED) data, which shows the unique structure-directing role of the OSDA in the formation of the intrinsic meso-microporous zeolite. This provides an incentive for preparing other stable mesopore-containing zeolites.

The structure of novel large pore borosilicate zeolite EMM-59 (|C₁₉H₄₂N₂|₈[B_5.2Si_218.8O₄₄₈]) with localized framework boron sites was determined by using three-dimensional electron diffraction (3D ED) and scanning transmission electron microscopy (STEM) imaging. EMM-59 was synthesized using 2,2-(cyclopentane-1,1-diyl)bis(N,N-diethyl-N-methylethan-1-aminium) as an organic structure-directing agent (OSDA). The framework has a three-dimensional intersecting channel system delimited by 12 × 10 × 10-ring openings and contains 28 T and 60 oxygen atoms in the asymmetric unit, making it the most complex monoclinic zeolite. The 3D ED data collected from as-made EMM-59 under cryogenic conditions revealed three symmetry-independent locations of the OSDAs, and STEM imaging showed that the OSDAs are flexible and adopt different molecular conformations in channels with identical structural environments. The framework boron atoms were exclusively found in T-sites of 4-rings, especially those shared by multiple 4-rings. The tetrahedral BO₄ with the highest boron content (38.6%) was transformed into a trigonal BO₃ after the OSDAs were removed upon calcination. Its location and boron content could also be identified by STEM imaging.