A Systematic Approach to Study Complex Ternary Co-Promoter Interactions: Addition of Ir, Li, and Ti to RhMn/SiO[sub.2] for Syngas Conversion to Ethanol

The direct conversion of synthesis gas could open up economically viable routes for the efficient production of ethanol. RhMn/SiO[sub.2] represents one of the most active systems reported thus far. Potential improvements were reported by added dopants, i.e., Ir, Ti, and Li. Yet, combining these elements leads to contradicting results, owing to the complexity of the interactions in a multi-promoted system. This complexity is often encountered in heterogeneous catalysis. We report a systematic data-driven approach for the assessment of complex multi-promoter interactions based on a combination of design-of-experiment, high-throughput experimentation, statistical analysis, and mechanistic assessment. We illustrate this approach for the system RhMn/SiO[sub.2] promoted with Ir, Li, and Ti. Using this approach, we investigate the impact of promoters’ interactions on a mechanistic level. Our analysis depicts the means to learn hidden correlations in the performance data and, additionally, high performance for ethanol yield for the RhMnIr/SiO[sub.2] catalyst. The method presented outlines an efficient way to also elucidate co-promoter interactions in other complex environments.