Calculational Study On Catalytic Characterization And Electronic Structure Of Hybrid Low-dimensional Materials

Catalytic conversion is critical for exploiting clean and renewable energy development and environmental protection.To date,the optimal catalysts are consisting of noble metal-based materials,whereas the high cost and scarcity prohibit its industrialized applications.Therefore,it is essential for sustainable development that the utilization of noble metal atoms was improved or alternative catalysts using inexpensive and earth-abundant elements was developed.Due to the strong quantum confinement effect,the low-dimensional materials exhibit novel atomic structures and electronic properties.Particularly,low-dimensional materials with well-defined geometrical structures,large specific surface area and high atomic utilization have great application prospects in the field of energy conversion.Consequently,it is of great significance to explore underlying mechanism governing the catalytic properties of low-dimensional materials for expanding their applications.In this work,we utilized the first-principles calculations to explore and understand the quantum size effects and interfacial coupling effects on low-dimensional materials for energy conversions,and established geometry–electronic structure–chemical activity correlation.These computational results provide an important theoretical basis for the atomically precise design and synthesis novel photo-or electro-catalysts with high performance.The results as the following:1)Through the first-principles combined high throughput screening calculations,we systematically explored the reaction pathway of 21 trimeric metal clusters anchored on nitrogen doped porous carbon materials for CO₂ reduction to C₂ and C₃ products.This trimeric metal clusters not only stably anchored on the underlying substrate by forming strong covalent interactions,but maintain their natural activities to co-adsorb two CO₂ molecules,which provides the unparalleled pathways for C–C coupling to yield multi-carbon products,and exhibits decent selectivity for high value-added products including ethanol,ethylene,propanol and propylene.Their surficial activity and selectivity can be precisely governed by interaction strength between trimeric metal clusters and underlying graphene substrate.2)We propose a new method to long-distance control the electrocatalytic behavior of supported metal nanoparticles by dispersing single metal atoms on an O-doped graphene.The charge density distributions of carbon substates can be efficiently regulated via introducing a single metal atom such as Fe,Co and Ni,which enhanced the strength of interfacial coupling between Ru nanoclusters and underlying carbon substates to improve the stabilities and performances of hydrogen evolution reaction for Ru nanoclusters.This result has been verified by experiments.3)The synergistic mechanism of core-shell structures of nitrogen-doped graphitic carbon materials and transition metals is revealed at the point of electronic structures.The chemical activity of hybrid systems depended on the C p_z band center,which were dually governed by the interfacial electronic coupling and local electronic injection of heteroatom.The p orbital center of nonmetal catalysts was proposed establishing the relationship between its surficial activity and electronic structure,which provides reasonable design and synthesis nonmetal-based catalysts with high performance.4)We explored that mono-and few-layer silicene supported by a Ag（111）substrate for CO₂ hydrogenation.As a result,surficial activity and selectivity of supported silicene dually governed by the substrate coupling and covalent interaction between silicene layers,which is depend on the number of layers of silicene.The supported silicene monolayer as a catalyst leads to the formation of CO,HCOOH and CHOH,while the formation of CH₄ and CH₃OH is favored on bilayer silicene.These theoretical results elucidate the fundamental principles for tailoring the activities of non-metal materials by controlling the number of layers and manipulating the surface states.5)Based on the first principle calculations combined ab initio nonadiabatic molecular dynamics simulations,we proposed that point defects in phosphorene can active its basal plane and optimize its optical absorption spectrum and photocarriers dynamics behavior.We elucidate the exact influence of each defect on the photocatalytic process.These results provide necessary knowledge for precisely design efficient nonmetal photocatalysts at the atomic level.