Models for heterogeneous catalysts: studies at the atomic level

Abstract

A systematic approach to model heterogeneous catalyst material and characterization at the atomic level is presented. Two examples are used to illustrate the concepts derived from those studies. They document the problems arising on the way to create such model systems and they also indicate possible solutions. The first example is connected with activation of CO 2 at the rim of electron rich MgO (thin film-supported Au islands), and the second example aims at the creation of a model system for the Phillips catalyst for ethylene polymerization and, in particular, the creation of a hydroxylated silica support.

The Interaction of CO2 with CeO2 Powder Explored by Correlating Adsorption and Thermal Desorption Analyses

“…Nevertheless, studies on clean and well-ordered surfaces lack important ingredients to successfully represent processes occurring in "real life" catalytic process. 27 TPD can also be used for the study of powders. Then, samples are heated (typically at 1−10 K/min) using an external oven, and the desorbing gas is generally transferred to a quadrupole mass spectrometer (QMS) detector through an inert gas.…”

“…Nevertheless, studies on clean and well-ordered surfaces lack important ingredients to successfully represent processes occurring in “real life” catalytic process . TPD can also be used for the study of powders.…”

Advances and challenges for experiment and theory for multi-electron multi-proton transfer at electrified solid–liquid interfaces

“…Fortunately, with present technology, we have enough supercomputers and equipment to make progress, as already shown in heterogeneous surface science at solid/gas interfaces. [48][49][50][51][52] In fact, several fascinating theoretical and computational approaches for electrode processes containing quantum effects in electron and proton transfer reactions were proposed since the late 1990s. [53][54][55][56][57][58][59][60][61][62][63][64][65][66] Therefore, we believe that the time for further advancement of quantum electrode process science, a scientific topic having a long tradition, has come.…”

“…One of the two ideas here is based on the ''classical'' theories for electronic interactions at heterojunctions systems, such as the work of Bardeen, 141 and of Cabrera and Mott, 142 or Vol'kenshtein's theory for heterojunction catalysts, 143 which has been extensively considered at solid/gas interfaces by Freund and his co-workers. 48,49,52,[144][145][146][147] The other idea is to use the advantage of MOFs/COFs, where electronic structures can be controlled by selections and combinations of organic monomers and metal ions. 100,119,132 The proof-of-concept was first shown for HER and ORR in 2017 ( Fig.…”

Quadrilaterals on the square screen of their diagonals: Regge symmetries of quantum mechanical spin networks and Grashof classical mechanisms of four-bar linkages

“…It is noteworthy also the application of four-bar mechanisms to engineering based on the emulation of the motion of animals, e. g. amphibian robots that mimic the skill of the basiliscus lizard to run on the water surface and walk on the ground (Rao et al 2013). For possible involvements in other areas of chemistry see also (Balzani et al 2017, Carrà 2017, Freund 2017, Zecchina et al 2017).…”