Nanosized Au Catalysts Supported on Mg(OH)<sub>2</sub>-CeO<sub>2</sub> for Preferential Oxidation of CO in Hydrogen Stream

Abstract

Preferential oxidation of carbon monoxide in the presence of hydrogen (PROX) is a promising method to remove CO from a hydrogen-containing gas mixture. Nanosized gold catalyst supported on CeO 2 and modified with Mg(OH) 2 was used for preferential oxidation of carbon monoxide in hydrogen-rich stream in this study. Mg(OH) 2 was added on CeO 2 by incipient-wetness impregnation. Au was loaded on Mg(OH) 2-CeO 2 by deposition-precipitation method. PROX reaction was carried out in a continuous flow, fixed bed reactor. CO/O 2 feed ratio was fixed at 1 to magnify the difference of various catalysts. The catalysts were characterized by N 2 sorption, TEM, HR-TEM and XPS. Mg(OH) 2 formed a thin layer on the surface of CeO 2. CeO 2 was in the crystalline phase and Mg(OH) 2 was amorphous. Au particles were homogeneously dispersed on the support with a size of 2-5 nm. Using CeO 2 as a support could increase the dispersion of Mg(OH) 2 and thus increase the interaction between Au and Mg(OH) 2. Adding Mg(OH) 2 on Au/CeO 2 could suppress H 2 oxidation and therefore increase CO oxidation activity.

A Multifunctional Au/CeO2-Mg(OH)2 Catalyst for One-Pot Aerobic Oxidative Esterification of Aldehydes with Alcohols to Alkyl Esters

“…In the 3AuM sample, this peak was observed at a weaker binding energy of 82.9 eV. The stronger binding energy of Au in the 3AuCM and 3AuC samples can be attributed to the SMSI effect between Au and the CeO 2 nanograins, whereas the weaker binding energy of Au in the 3AuM sample indicated weaker interactions between Au and the Mg(OH) 2 surface [58]. In the Mg 2p region (Figure 3B), two peaks corresponding to MgO and Mg(OH) 2 were observed in the 3AuM and 3AuCM samples.…”

“…The SMSI effect between Au and CeO2 can be evidenced via XPS, which also provides deeper insights into the electronic structures of the catalyst surfaces (Figure 3). The Au 4f7/2 peaks are generally observed in a binding energy range of 83-85 eV [41,57,58]. For the The SMSI effect between Au and CeO 2 can be evidenced via XPS, which also provides deeper insights into the electronic structures of the catalyst surfaces (Figure 3).…”

“…For the The SMSI effect between Au and CeO 2 can be evidenced via XPS, which also provides deeper insights into the electronic structures of the catalyst surfaces (Figure 3). The Au 4f 7/2 peaks are generally observed in a binding energy range of 83-85 eV [41,57,58]. For the 3AuCM sample, a 4f 7/2 peak appeared at 84.0 eV, which corresponded to the metallic Au(0) species (Figure 3A).…”