Unraveling the structure sensitivity in methanol conversion on CeO2: A DFT + U study

Abstract

<p> <span style="color: rgb(80, 80, 80); font-family: Arial, Helvetica, &quot;Lucida Sans Unicode&quot;, &quot;Microsoft Sans Serif&quot;, &quot;Segoe UI Symbol&quot;, STIXGeneral, &quot;Cambria Math&quot;, &quot;Arial Unicode MS&quot;, sans-serif; font-size: medium;">Methanol decomposes on oxides, in particular CeO</span><span style="box-sizing: border-box; position: relative; top: 0.4em; vertical-align: baseline; color: rgb(80, 80, 80); font-family: Arial, Helvetica, &quot;Lucida Sans Unicode&quot;, &quot;Microsoft Sans Serif&quot;, &quot;Segoe UI Symbol&quot;, STIXGeneral, &quot;Cambria Math&quot;, &quot;Arial Unicode MS&quot;, sans-serif;">2</span><span style="color: rgb(80, 80, 80); font-family: Arial, Helvetica, &quot;Lucida Sans Unicode&quot;, &quot;Microsoft Sans Serif&quot;, &quot;Segoe UI Symbol&quot;, STIXGeneral, &quot;Cambria Math&quot;, &quot;Arial Unicode MS&quot;, sans-serif; font-size: medium;">, producing either formaldehyde or CO as main products. This reaction presents structure sensitivity to the point that the major product obtained depends on the facet exposed in the ceria nanostructures. Our density functional theory (DFT) calculations illustrate how the control of the surface facet and its inherent stoichiometry determine the sole formation of formaldehyde on the closed surfaces or the more degraded by-products on the open facets (CO and hydrogen). In addition, we found that the regular (1</span><span style="color: rgb(80, 80, 80); font-family: Arial, Helvetica, &quot;Lucida Sans Unicode&quot;, &quot;Microsoft Sans Serif&quot;, &quot;Segoe UI Symbol&quot;, STIXGeneral, &quot;Cambria Math&quot;, &quot;Arial Unicode MS&quot;, sans-serif; font-size: medium;">0</span><span style="color: rgb(80, 80, 80); font-family: Arial, Helvetica, &quot;Lucida Sans Unicode&quot;, &quot;Microsoft Sans Serif&quot;, &quot;Segoe UI Symbol&quot;, STIXGeneral, &quot;Cambria Math&quot;, &quot;Arial Unicode MS&quot;, sans-serif; font-size: medium;">0) termination is the only one that allows hydrogen evolution via a hydride&ndash;hydroxyl precursor. The fundamental insights presented for the differential catalytic reactivity of the different facets agree with the structure sensitivity found for ceria catalysts in several reactions and provide a better understanding on the need of shape control in selective processes.</span></p>