The Effect Of ZnO Addition On Co/C Catalyst For Vapor And Aqueous Phase Reforming Of Ethanol

Journal Article · Wed Feb 05 00:00:00 EST 2014 · Catalysis Today

DOI:https://doi.org/10.1016/j.cattod.2013.12.044· OSTI ID:1158457

Davidson, Stephen ^[1]; Sun, Junming ^[1]; Hong, Yongchun ^[2]; Karim, Ayman M. ^[3]; Datye, Abhaya K. ^[4]; Wang, Yong ^[2]

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1. Washington State Univ., Pullman, WA (United States)
2. Washington State Univ., Pullman, WA (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
3. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
4. Univ. of New Mexico, Albuquerque, NM (United States)

The effect of ZnO addition on the oxidation behavior of Co along with catalytic performance in vapor and aqueous phase reforming of ethanol were investigated on Co supported on carbon black (XC-72R). Carbon was selected to minimize the support interactions. Effect of ZnO addition during both vapor and aqueous phase reforming were compared at 250 °C. ZnO addition inhibited the reduction of cobalt oxides by H₂ and created surface sites for H₂O activation. During vapor phase reforming at 450 °C the redox of cobalt, driven by steam oxidation and H₂ reduction, trended to an equilibrium of Co0/Co²⁺. ZnO showed no significant effect on cobalt oxidation, inferred from the minor changes of C₁ product yield. Surface sites created by ZnO addition enhanced water activation and oxidation of surface carbon species, increasing CO₂ selectivity. At 250 °C cobalt reduction was minimal, in situ XANES demonstrated that ZnO addition significantly facilitated oxidation of Co⁰ under vapor phase reforming conditions, demonstrated by lower C₁ product yield. Sites introduced by ZnO addition improved the CO_x selectivity at 250 °C. Both Co/C and Co-ZnO/C rapidly oxidized under aqueous phase reaction conditions at 250 °C, showing negligible activity in aqueous phase reforming. This work suggests that ZnO affects the activation of H₂O for Co catalysts in ethanol reforming.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1158457
• Report Number(s): PNNL-SA-105228; KP1704020
• Journal Information: Catalysis Today, Vol. 233; ISSN 0920-5861
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

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