Selox catalysts

250 I 10 Combinatorial Strategies for Speeding up Discovery and Optimization of Heterogeneous Catalysts 

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As a second example using the DoE assistant tool for designing libraries, the first library of 48 diverse Selox catalysts (Tab. 10.2, Section 10.2.4.2) was tested in both the presence and absence of hydrogen to evaluate the impact of operating conditions on Selox performance [18]. From the set of data giving the conversion of CO (not reported here), an analysis of the effect induced by the four selected factors (alkali addition, type of support, nature of the transition metals and of the noble metal binaries) was carried out following different models [18]. 

Cons Data quality for HT synthesis and testing (reproducibility, homogeneity, scale-up ability), as shown for this case of metals/mixed oxides WGS and Selox catalysts, remains a drawback for efficient data-mining. As such, even if the trends for new catalytic formulas may still be detected, even in the presence of poorly reproducible systems or outliers, the ultimate target of predicting the quantitative performance of a catalyst after teaching an ANN with experimental data was found to require new catalysts descriptors that would contain more information than the simple elemental composition of the materials. 

Fundamental understanding of structure-function relationships is central for the design of improved selox catalysts, and has been greatly assisted by the development of new analytical tools with which to probe active sites at subnanometer spatial resolution [36] and subsecond time resolution. X-ray-based methods in particular can provide detailed insight into chemical composition and environment of active components and reacting adsorbates [140-142]. Quick and dispersive XAS have the capabihty to monitor dynamic changes in catalyst structure under reaction conditions (so-caUed operando spectroscopy) and have been applied to alcohol selox over Pd [96, 143-146], Pt [67, 147], and Ru [147] nanoparticles. 

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