Atomic layer deposition (ALD) can atomically tailor the shape and size of metal nanoparticles (NPs) during nucleation. If ultrathin metal films are desired, nucleation enhancement is crucial to obtain layer closure at low film thickness. However, state-of-the-art insights only offer information on the NP size and coverage in the late stages of nucleation, lacking fundamental knowledge on the initial nucleation density and atomic 3D structure of the nuclei in the very early stages of ALD growth, which inhibits nucleation control. In this proposal, our aim is to exploit the developed GIPDF methodology to uncover the role of different parameters which can influence and enhance ALD nucleation of Pt NPs, namely (1) surface pretreatment, (2) photo-assisted ALD, and (3) applying an ill-understood Pt(acac)2-O3 ALD process. By atomistic modelling of the GIPDF data, insights will be extracted which will guide controlled nucleation towards atomically tailored NPs or ultrathin metal films.

During catalytic reactions, heat is released on or extracted from the catalyst. This leads to strong catalyst temperature changes, on its turn triggering restructuring and undesired side reactions. Here, XRD will be pioneered as novel tool in combination with XAS to probe the temperature of metal nanoparticles and the support for the first time selectively and operando in real-time. By monitoring the changes in the lattice spacing (XRD) and the Debye-Waller factor (XAS), thermally induced lattice expansion/disorder will be linked to the temperature. This will enable to unravel temperature heterogeneities in the catalyst, chart heat transport and reaction rates, and in general provide a first-of-its-kind temperature bookkeeping in catalysis.

The controlled preparation of supported nanoparticles (NPs) by atomic layer deposition (ALD) requires a fundamental understanding and careful tuning of nucleation processes. The state-of-the-art insights into the morphological evolution of metal NP populations on oxides during ALD cover the NP size and coverage (#NPs/cm2), but currently lack information on the atomic 3D structures and surface structures of the NPs. Herein, GIPDF will be used to uncover the atomic structure of Pt NPs, from sub-nm clusters to crystalline facetted NPs, for different ALD chemistries. This approach will allow us to understand the structural response of the nuclei and NPs to the surface chemical reactions in ALD, which will be linked to information on the growth kinetics to elucidate how the NP structure and surface reactivity in ALD are intertwined.

Metal nanoparticle (NP) sintering is a prime cause of catalyst degradation, limiting its economic lifetime and viability. During sintering, the average NP size increases but strong debate exists on which mechanism causes sintering, being either (i) NP migration and coalescence or (ii) Ostwald ripening by atomic transport between immobile NPs. Herein, the aim is to extract first-of-its-kind insights on the role of NP migration during NP sintering. By applying GIXPCS-GISAXS under true working conditions of the catalyst, the NP migration rate will be monitored in conjunction to its size evolution under different reaction conditions, allowing to unravel which mechanism governs NP sintering. This approach has never been applied in NP catalysis, and will unambiguously answer long-standing, foundational questions on NP sintering.

Datasets and Python scripts used for the plots and claims made in the manuscript "All-polarisation beamsplitters for interferometer application" submitted to Physical Review Research. The dataset is split into three parts corresponding to the three measurement subsections of the paper: II.A. Coating decomposition (contact Jorden De Bolle), II.B. Power-splitting ratio (contact Zeb Van Ranst), II.C. Dark fringe (DF) offset (contact Luise Kranzhoff).

Datasets and Python scripts used for the plots and claims made in the manuscript "All-polarisation beamsplitters for interferometer application" submitted to Physical Review Research. The dataset is split into three parts corresponding to the three measurement subsections of the paper: II.A. Coating decomposition (contact Jorden De Bolle), II.B. Power-splitting ratio (contact Zeb Van Ranst), II.C. Dark fringe (DF) offset (contact Luise Kranzhoff).