Title: Two-Dimensional Materials: Interfaces, Edges, and Dopants

Speaker: Geert Brocks (CCER, Twente)
Time: Feb. 13, 2020, 10:00–11:00
Location: Differ, Alexander-zaal

In the wake of graphene, many different types of two-dimensional (2D) materials have been grown or isolated. Monolayers of transition metal di-chalcogenides (TMDCs) MX2, with M=Mo,W, X=S,Se,Te, are direct semiconductors with sizeable band gaps in the range of 1 to 2 eV. Applications in devices not only demand a control over the 2D material’s quality, but also call for carefully designed interfaces with the surroundings, such as metal contacts. I will explain a strategy for making zero-barrier contacts, based upon theoretical insight and DFT calculations, which has meanwhile been verified experimentally. Edges and grain boundaries of TMDC islands often display a one-dimensional (1D) metallic character, which is robust against reconstructions or stoichiometric variations of the edges, and can lead to catalytic activity. I will discuss the origin and type of such 1D metals, and show how to manipulate them. The catalytic activity of a 2D material can be enhanced by transition metal (TM) doping. Time permitting, I will show you how this is done in TM-doped GaN.

The CCER seminars are aimed at researchers interested in computational approaches to (energy) research. The seminar is small-scale, typically 15 participants, and interactive, offering lots of room for discussion. If you don't have access to the DIFFER building but would like to attend, just This email address is being protected from spambots. You need JavaScript enabled to view it. .

Title: Engineering Porous Materials for Electrochemical Energy Conversion and Storage.

Speaker: Antoni Forner-Cuenca (TU/e, Dept. of Chemical Engineering and Chemistry, group Electrochemical Porous Materials & Interfaces, group Membrane Materials & Processes)
Time: Jan.23, 2020, 10:00–11:00
Location: Differ, Alexander-zaal

Abstract | Electrochemical processes are poised to play a pivotal role in the evolving global power system because the efficient interconversion of electrical and chemical energy can enable the development of green technologies that support the decarbonization of the electric grid, power the automotive fleet, and offer new opportunities for chemical manufacturing. Porous materials (e.g. electrodes) are central to advanced electrochemical systems as they are responsible for multiple critical functions in the cell related to thermodynamics, kinetics, and transport. They provide surfaces for electrochemical reactions, conduct electrons and heat, and distribute fluids. Thus, their design governs the performance, durability, and consequently, the cost of these systems. In this seminar, I will present my recent research efforts to develop advanced porous materials for polymer electrolyte fuel cells (PEFCs) and redox flow batteries (RFBs). First, I will discuss the fabrication, characterization, and performance of novel gas diffusion layer materials with patterned wettability to optimize the water and gas transport in PEFCs. Then, I will discuss my current efforts to develop advanced electrodes for nonaqueous RFB through understanding the role of electrode microstructure and surface chemistry.

Bio | Dr. Antoni (Toni) Forner-Cuenca recently started his appointment as Assistant Professor at Eindhoven University of Technology. Prior to that, Toni was a postdoctoral fellow in the Department of Chemical Engineering at the Massachusetts Institute of Technology under Prof. Fikile R. Brushett, where he focused on developing advanced porous electrodes for redox flow batteries. Toni received his Ph.D. from ETH Zürich (Switzerland) in 2016 where he worked with Dr. Pierre Boillat and Prof. Thomas J. Schmidt on developing novel gas diffusion layers with patterned wettability for advanced water management strategies in polymer electrolyte fuel cells. Toni has been the recipient of the ETH Zurich Medal 2017, the Electrochemical Society Energy Technology Graduate Student Award 2017, and the Swiss National Science Foundational Postdoctoral Mobility Fellowship.

The CCER seminars are aimed at researchers interested in computational approaches to (energy) research. The seminar is small-scale, typically 15 participants, and interactive, offering lots of room for discussion. If you don't have access to the DIFFER building but would like to attend, just This email address is being protected from spambots. You need JavaScript enabled to view it..

Title: Fusion plasma turbulence simulation with neural network surrogate models

Speaker: Jonathan Citrin (DIFFER)
Time: Dec. 19, 2019, 10:00–11:00
Location: Differ, Alexander-zaal

Abstract
Plasma energy losses due to turbulent transport is one of the limiting factors for achieving viable fusion energy. Reactor design and plasma scenario optimisation demands both accurate and tractable predictive turbulence calculations.

Title: Modelling plasma and neutral gas dynamics in tokamak divertors and linear divertor simulators

Speaker: Egbert Westerhof (DIFFER)
Time: Nov 28, 2019, 10:00–11:00
Location: Differ, Alexander-zaal

Abstract
In any fusion energy reactor the hot plasma from the core of the reactor, where the fusion reactions occur, must be cooled down before it comes into contact with the reactor wall. In a magnetic confinement fusion reactor like a tokamak, the plasma flowing along the magnetic field lines outside the so-called ‘last-closed-flux-surface’ is diverted towards target plates well separated from the main plasma. Such a magnetic topology is called a divertor and allows to localize the plasma material interaction to a region where it can be controlled in order to prevent wall materials from entering the core plasma. In this presentation I will address the modelling of the plasma and neutral gas dynamics in tokamak divertors and in linear divertor simulators. I will present some of the main research and development issues that are being addressed for the design of a viable fusion energy reactor.

The CCER seminars are aimed at researchers interested in computational approaches to (energy) research. The seminar is small-scale, typically 15 participants, and interactive, offering lots of room for discussion. If you don't have access to the DIFFER building but would like to attend, just This email address is being protected from spambots. You need JavaScript enabled to view it..