Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Ujjal Das Project Name: 1atomCat Division: MSD Project title: Supported Single-Site Catalysts for Activation of Small Molecules Associated funding: BES Chemical Sciences Other Systems: CNM Carbon cluster - 100,000 cpu hrs. Science: This proposal requests a renewal of our previous proposal titled "Supported Single-Atom Catalysts for Activation of Small Molecules". The computational resources from the previous allocation were used to study the structure of catalyst active site of silica supported first-row transition metal catalysts (M/SiO2, M = Fe, Co, Zn) and reaction mechanisms of alkane dehydrogenation and alkene hydrogenation. In particular, we identified key defect sites on amorphous silica surfaces as binding sites for metals. We have also identified novel mechanisms for H-H and C-H bond activation in H2 and propane by single-site silica supported Fe(II), Zinc(II), and Co(II) catalysts. The current proposal requests for additional resources which will be used to investigate catalytic non-oxidative coupling of methane. The discovery and development of large reserves of shale gas, consisting of mostly methane, ensures that the selective utilization of methane will remain a target for large scale energy production. Any approach which can incorporate methane into transportable material for fuels and fine chemicals would be a dramatic breakthrough for the energy sector. Our approach is to study the fundamental reaction methane + olefin = larger alkanes. Mechanistic insight into the fundamental processes of methane interaction with the metal and subsequent addition to alkenes will guide the development of new single-site catalysts that are thermodynamically compatible and exhibit activity and selectivity required for practical applications. Project description: For methane homologation, density functional calculations will be used to investigate all possible reaction pathways leading to C-C coupling such as (1) activation of methane by metal catalyst followed by alkene insertion or (2) addition of alkene followed by methane insertion. Mechanism of possible side reactions that may reduce catalyst selectivity will be studied. They include dehydrogenation of the product alkane, polymerization of alkene precursors, and formation of aromatics. Mechanistic insights obtained from these studies will be used to screen numerous single-site catalysts. In particular, the calculations will focus on significantly lowering the activation barrier for C-C coupling while increasing the activation barrier for alkane dehydrogenation to ensure high activity and selectivity for methane homologation. We will perform density functional theory (DFT) calculations to determine structure, bonding, and reaction energies of the system. Periodic boundary condition (PBC) will be imposed in order to maintain periodicity of the solid support. Gradient corrected PBE density functional will be used for these calculations. The Nudged Elastic Band (NEB) method of Henkelman and coworkers will be used to calculate transition states and activation barriers for formation of different surface species. Surface phonons will be calculated for accurate estimation of reaction free energies. We will primarily use the DFT code implemented in VASP (for periodic calculations) and Gaussian package. Both VASP and Gaussian run in parallel mode. For the MPI version of VASP, increased efficiency is observed up to 32 processors. The Linda version of Gaussian scales up to 32 processors. Energy optimization in VASP takes approximately 750 CPU hours and we plan roughly 200 of such calculations. Hessian (second order energy derivative) evaluation takes roughly 1600 CPU hours and we plan to run 50 of these calculations. Optimization and Hessian evaluation using Gaussian program take approximately the same time for model clusters. We estimate that we will have to run a total of 300 Gaussian calculations, each taking 400 CPU hours. So our total request is 350,000 core hours. Industry partnership: Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 320000 Q1: 80000 Q2: 80000 Q3: 80000 Q4: 80000 Justification: Storage requirements: Thank You, The LCRC Accounts System