From Molecules to Process Applications. A strategic project of the NT -Faculty at NTNU for three Chemistry Departments

The primary objective of the project was to build applied computational chemistry in Norway, drawing on the excellent expertise of experimental groups in catalysis, electrocatalysis, material science , membrane separation and CO2 capture and sequestration. The project delivered 6 PhD theses and trained 1 postdoc, and promoted international exchange in the field of computational chemistry, using also the enthusiasm of committed partners abroad. The main scientific outcomes are summarized below. Development of lead-free piezoelectric materials: The microscopic origin of polarization in an important class of piezoelectric materials, tetragonal tungsten bronzes, has been identified by a combination of first principle DFT simulations and experiments. Two different mechanisms were identified, the first related to the presence of lone-pair elements like lead or bismuth and the second related to distortion of octahedral building units in the crystal structure. Moreover, the study also included how cation order-disorder and thermal history of the materials can influence the polarization (Prof. Grande, PhD thesis Olsen). Fischer-Tropsch (FT) synthesis on Co-nanoparticles: We demonstrated that the combined approach of DFT, kinetic analysis and kinetic isotope effect analysis is a powerful method to discriminate the possible mechanisms for FTS, including CO activation, methane formation, chain growth, carbon number dependence of olefin and paraffin formation and water effects on chain growth (Prof. Chem, PhD thesis Qi). Interactions between carbon surfaces and metal atoms were investigated by quantum chemical calculations to study how the carbon material affects the catalytic properties of the metals. It has been demonstrated by doping of the carbon structures, e.g. by oxygen, that the catalytic properties of the metal substrate can be tuned and thereby that we can optimize the catalyst by modifying the carbon material (Prof. Åstrand, PhD thesis Mahmoodinia). Multi-Scale Modeling of Adsorption at Liquid-Liquid Interfaces: We performed DFT simulations of the interactions between carboxylate and calcium ions and implementation of those results to calculate the fractional interfacial conversion of calcium-tetracarboxylic acid precipitates. These studies revealed the ionic interactions in (a) a vacuum, (b) in the presence of water molecules, (c) the probability of complexation of calcium and tetracarboxylic acid based on separation distance, and (d) a course grained representation of interfacial calcium-tetracarboxylic acid precipitations. The results from this multiscale modeling effort addressed crude oil flow assurance problems at a process scale level with calculations obtained at the atomic scale (Prof. Grimes, PhD thesis Mehandzhiyski). Simulating CO2 Separation in Molecular Sieve Membranes: Experimental groups at NTNU have developed membranes from carbon fibers, for the purpose of separating CO2 from industrial off-gases. The properties of the membranes were investigated using molecular simulations. Among new findings, we found it interesting that CO2 adsorbs in two distinct layers. This knowledge is important for the understanding of transport properties. The transport was not much affected by temperature gradients, but was sensitive to absolute temperature. We developed a new method to find thermodynamic data of the adsorbed layer. Such information is central in simulations of the membrane process (Prof. Kjelstrup, postdoc Trinh). Rational nanodesign of catalysts: Coupled cluster theory is one of the most accurate, but also one of the most computationally demanding methods currently available in electronic structure theory. Multilevel coupled cluster theory can greatly reduce the cost by treating only a part of the molecule with a high-level theory and the rest more approximately. We have demonstrated how coupled cluster models can be combined with novel experimental techniques to follow the evolution of excited states in thymine. We achieved almost two orders of magnitude reductions in computational cost with this approach (Prof. Koch, PhD thesis Heilemann) Another approach was the study of dynamics of chemical reactions in solution based on path sampling and Ab Initio MD. In particular, we applied the Replica Exchange Transition Interface Sampling method, was so-far was never applied to a large Ab Initio level system. Using this technique, we revealed surprising reaction steps in the silicate oligomerization reactions, contradicting earlier results based on traditional methods, that do not reveal the spontaneous dynamics of the system. Also, the approach was also applied to study the auto-ionization of liquid water (Prof. van Erp, PhD thesis by Moqadam).

This project, which has a national and international embedding, is the first answer of the NT Faculty to the national follow-up commision of the Hey-Hawkins report. It describes the Faculty's plan to bring in new activity and revitalise the chemistry dep artmens by employing two new professors and funding 8 graduate students and 1 post doc in computational chemistry including all 3 departments. The own allocation is considerable (30.7 mill NOK). Support amounting 8.0 mill NOK is asked for, so as to link new collaborators in experimental and computational fields and to strengthen the competence in computational chemistry. Density functional theory, reactive force fields, molecular and Monte Carlo simulations and chemometrics shall be used to study equili brium and transport problems on large scale computers (the NOTUR facilities). Breakthrough results are expected in the fields of ferroic materials, electrocatalysis, carbon sieve membranes for cheap sequestration of CO2, Fischer-Tropsch catalysis on step ped Co surfaces, and CO2 capturing solvents, all topics of central national and international importance. The project follows the advice of the NFR appointed national commitee, because it I. strengthens computational chemistry (statistical mechanics) at NTNU and takes advantage of existing infrastructure (NOTUR) II. proposes new interdisciplinary collaborations for partners in computational chemistry, materials science and chemical engineering, leading to renewal in three chemistry departments III. integrate the computational activity with experimental efforts in materials science and process chemistry, giving NTNU a unique applied chemical profile IV. proposes a substantial increase in nanoscience at NTNU V. adds basic research to chemical engine ering and electrochemistry research working on the climate challenge (CO2) and electrochemical technology VI. strengthens existing and brings in new expertise in catalysis and electrocatalysis