GOALI: Molecular Modeling of Confined Nano-Phases and Novel Nano-Porous Materials

North Carolina State University, Raleigh NC

Investigators

Abstract

0932656 Gubbins This is a GOALI project involving university-industry collaboration between researchers at North Carolina State University (NCSU) and at Quantachrome Instruments, a leading maker of instruments for characterizing nano-structured materials. The aim of this project is to develop and apply atomistic simulation methods to obtain realistic atomic models for several new classes of synthetic nanoporous materials, and to use these to investigate confined phases within these materials and to assist in optimization of the materials for specific applications. The materials to be studied are carbide-derived carbons, mesoporous carbons and silicas, and hierarchical carbons and silicas. These materials hold promise for energy-related applications in hydrogen storage, catalysis, microelectronics (mesoporous silicas), and as electrodes in fuel cells, batteries and supercapacitors (carbide-derived carbons, mesoporous and hierarchical carbons). Accurate and realistic atomic models of these materials are essential to the development of optimal material designs for these applications. Preparation of these materials and experimental studies of structure and adsorption on them will be performed by researchers at Quantachrome Instruments, and this data will be provided to the NCSU researchers. Quantachrome scientists will also offer advice on directions for the modeling work carried out at NCSU. The NCSU researchers will develop and test a new simulation methodology, Hybrid Reverse Molecular Dynamics, for building realistic atomistic models of these materials. Monte Carlo and molecular dynamics simulations will be carried out to study adsorption in these materials, and of diffusion in the carbide-derived carbons and hierarchical carbons and silicas. In the case of the carbon materials, molecular simulations will be carried out to determine their performance as supercapacitors, including studies of capacitance, power density and diffusion in the pore structures, with the aim of understanding the influence of pore design on performance. Intellectual Merit. Because these novel materials are not crystalline, a combination of atomistic simulation and experiment provides the best route to developing realistic atomic models of them. Existing models of such materials assume over-simplified pore geometries (slit or cylinder shaped) and are inadequate for predicting the behavior of adsorbed phases. The realistic models that are being developed will make possible fundamental investigations of the influence of confinement and nature of the material on adsorption, phase changes, diffusion, reactions and electrode performance. Broader Impact. Improved understanding of the behavior of nano-phases confined within these novel nano-porous materials will impact a broad range of technologies, and is essential to the design of new biological and chemical sensors, nano-reactors, hydrogen storage media, electrodes for fuel cells and batteries, and nano-structured catalysts. Graduate and undergraduate students working on this project will learn modern multi-scale modeling methods, and will gain experience of international cooperative research through our active collaborations in this area with researchers in Japan, Poland, China and Hong Kong. Graduate students from under-represented groups will be recruited through a bridging program and an existing AGEP program with nearby HBCUs.