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CeO2-based catalysts commonly suffer from weak NH3 adsorption, which leads to inferior activity at medium/low temperatures for the selective catalytic reduction (SCR) of NO with NH3. Doping and loading onto a suitable support are two effective means to promote the NH3 adsorption of CeO2-based materials. However, using traditional trial-and-error experimental methods via dopants to enhance NH3 adsorption is generally time-consuming and inefficient. Here, by means of DFT calculations, we successfully screened two elements (Mo and Cu) for doping into CeO2. With electronic analysis, the underlying mechanism of NH3 adsorption properties was well-illustrated. However, silicalite-1 with a stable ultrahigh specific surface area was synthesized to support CeO2 for the first time, enabling CeO2 to have a high accessible reactive surface area. All the experimental NH3-TPD, in situ DRIFTS, and NO x conversion catalytic activity results support our DFT calculations and the proposed mechanism. Our combined theoretical–experimental study proposes rational screening strategies for NH3–SCR from DFT calculations to experimental studies, thus providing insight into the development of CeO2-based SCR catalysts.

A series of CeOx catalysts supported by commercial porous cordierite ceramics (CPCC) and synthesized porous cordierite ceramics (SPCC) from fly ash were prepared for selective catalytic reduction of NOx with ammonia (NH3-SCR). A greater than 90% NOx conversion rate was achieved by the SPCC supported catalyst at 250–300 °C when the concentration of loading precursor was 0.6 mol/L (denoted as 0.6Ce/SPCC), which is more advantageous than the CPCC supported ones. The EDS mapping results reveal the existence of evenly distributed impurities on the surface of SPCC, which hence might be able to provide more attachment sites for CeOx particles. Further measurements with temperature programmed reduction by hydrogen (H2-TPR) demonstrate more reducible species on the surface of 0.6Ce/SPCC, thus giving rise to better NH3-SCR performance at a low-temperature range. The X-ray photoelectron spectroscopy (XPS) analyses reveal that the Ce atom ratio is higher in 0.6Ce/SPCC, indicating that a higher concentration of catalytic active sites could be found on the surface of 0.6Ce/SPCC. The in situ diffused reflectance infrared fourier transform spectroscopy (DRIFTS) results indicate that the SCR reactions over 0.6Ce/SPCC follow both Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms. Hence, the SPCC might be a promising candidate to provide support for NH3-SCR catalysts, which also provide a valuable approach to recycling the fly ash.

Energy-intensive industries (EIIs) refer to industries that are highly dependent on energy (fuel), which are primarily responsible for industrial energy consumption [...]