PNNL

Abstract

Converting high-performing powder catalysts at the laboratory reactor scale into effective extruded catalysts at the industrial scale remains a significant hurdle for advancing novel sustainable catalytic processes, such as the conversion of biogenic syngas into high octane gasoline. Recently, a process-intensified syngas-to-hydrocarbons (STH) reaction in a single reactor under relatively mild conditions (220–250 ºC, 0.75–2.0 MPa) was reported, enabled by the development of a dimethyl ether (DME) homologation catalyst, Cu-modified H-BEA (Cu/BEA) zeolite. In this study, we explore approaches for synthesizing engineered Cu/BEA catalysts for use in the STH reaction to retain the high performance observed with the powder catalyst. We demonstrate that minor changes in the specific order of manufacturing steps (Cu deposition, alumina binder addition, and extrusion) result in dramatic changes in key active sites (Brønsted acid sites and zeolitic Cu+ species), and ultimately, the catalyst performance. When the Cu precursor was added directly to BEA before extrusion, these active sites were stabilized, preserving the activity of the powder catalyst. However, when the Cu precursor was added after extrusion, the resulting Cu species became mobile, destabilizing Brønsted acid sites and leading to near-zero activity.