The chemical conversion of small molecules such as H2, H2O, O2, N2, CO2, and CH4 to energy and chemicals is critical for a sustainable energy future. However, the high chemical stability of these molecules poses grand challenges to the practical implementation of these processes. In this regard, computational approaches such as density functional theory, microkinetic modeling, data science, and machine learning have guided the rational design of catalysts by elucidating mechanistic insights, identifying active sites, and predicting catalytic activity. Here, the theory and methodologies for heterogeneous catalysis and their applications for small‐molecule activation are reviewed. An overview of fundamental theory and key computational methods for designing catalysts, including the emerging data science techniques in particular, is given. Applications of these methods for finding efficient heterogeneous catalysts for the activation of the aforementioned small molecules are then surveyed. Finally, promising directions of the computational catalysis field for further outlooks are discussed, focusing on the challenges and opportunities for new methods.

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Despite the technological importance of colloidal covalent III-V nanocrystals with unique optoelectronic properties, their synthetic process still has challenges originating from the complex energy landscape of the reaction. Here, we present InP tetrapod nanocrystals as a crystalline late intermediate in the synthetic pathway that warrants controlled growth. We isolate tetrapod intermediate species with well-defined surfaces of (110) and ($$\bar{1}\bar{1}\bar{1}$$ 1 ¯ 1 ¯ 1 ¯ ) via the suppression of further growth. An additional precursor supply at low temperature induces $$[\bar{1}\bar{1}\bar{1}]$$ [ 1 ¯ 1 ¯ 1 ¯ ] -specific growth, whereas the [110]-directional growth occurs over the activation barrier of 65.7 kJ/mol at a higher temperature, thus finalizes into the (111)-faceted tetrahedron nanocrystals. We address the use of late intermediates with well-defined facets at the sub-10 nm scale for the tailored growth of covalent III-V nanocrystals and highlight the potential for the directed approach of nanocrystal synthesis.

Supported Ni-based nanocatalysts have attracted much attention to replace noble metal catalysts (e.g., IrO2) for the oxygen evolution reaction (OER) due to their low costs. However, their low activity is the main hindrance for their use in the practical OER application. In this study, a Ni-based core–shell material (Ni@Ni-NC) is produced through the heat treatment of a mixture of urea and NiCl2·(H2O)6. Multiple analysis data reveal that the Ni@Ni-NC consists of a Ni nanoparticle core and several tens of nanometer-thick, N-doped carbon (NC) shell materials, in which atomically attached Ni-based species were homogeneously distributed. Ni@Ni-NC exhibits excellent electrocatalytic OER performance with over- and onset potentials of 371 mV and 1.51 V, respectively, which are better than those of commercial IrO2. As control samples, structural and electrochemical properties of various composites (Ni nanoparticles + N-doped graphene, Ni nanoparticles + C3N4, atomically dispersed Ni on a C3N4 surface) and acid-treated Ni@Ni-NC are investigated. These experiments reveal that the well-dispersed Ni–NC species and core–shell structures play pivotal roles in improving the electrocatalytic OER performance. Furthermore, density functional theory (DFT) calculations suggest the dual-site OER mechanism of the Ni–NC active species with a significantly low reaction barrier. The mechanisms for the formation of core–shell structures are studied with control samples, which are produced from different heating times, and DFT calculation suggested that the core/shell structure formation is attributed to the cohesive energy of the Ni particles and strong bonds between the Ni and NC supports. This work provides a facile strategy for designing supported Ni catalysts with core–shell architecture for electrocatalytic reactions and other advanced applications.

Strain engineering of perovskite quantum dots (pQDs) enables widely tunable photonic device applications. However, manipulation at the single-emitter level has never been attempted. Here, we present a tip-induced control approach combined with tip-enhanced photoluminescence (TEPL) spectroscopy to engineer strain, bandgap, and the emission quantum yield of a single pQD. Single CsPbBr x I 3−x pQDs are clearly resolved through hyperspectral TEPL imaging with ∼10 nm spatial resolution. The plasmonic tip then directly applies pressure to a single pQD to facilitate a bandgap shift up to ∼62 meV with Purcell-enhanced PL increase as high as ∼10 5 for the strain-induced pQD. Furthermore, by systematically modulating the tip-induced compressive strain of a single pQD, we achieve dynamical bandgap engineering in a reversible manner. In addition, we facilitate the quantum dot coupling for a pQD ensemble with ∼0.8 GPa tip pressure at the nanoscale estimated theoretically. Our approach presents a strategy to tune the nano-opto-electro-mechanical properties of pQDs at the single-crystal level.