A nanoscale Ni/ZrO2 catalyst coated with Al2O3 for carbon dioxide reforming of methane. Issue 2 (19th September 2020)

• Record Type: Journal Article
• Authors: Wang, Xiaorui; Bai, Xiaoli; Guo, Yu; Liu, Qirui; Ji, Shengfu; Wang, Zhou‐jun
• Is Part Of: Journal of chemical technology & biotechnology. Volume 96:Issue 2(2021)
• Page Start: 474
• Page End: 480
• Publication Date: 2020-09-19
• Subjects: carbon utilization -- catalyst preparation -- energy -- heterogeneous catalysis; Biotechnology -- Periodicals; Chemistry, Technical -- Periodicals; Chemical engineering -- Periodicals; Industries -- Environmental aspects -- Periodicals; 660
• DOI: 10.1002/jctb.6562
• Languages: English
• ISSNs: 0268-2575

Abstract

Abstract: BACKGROUND: CO2 reforming of methane, also known as dry reforming of methane, has received significant attention because this technology can convert notorious greenhouse gases (CH4 /CO2 ) into useful syngas (H2 /CO). However, this technology still has not been commercialized, primarily due to the lack of feasible catalysts. RESULTS: Based on zirconia (ZrO2 ) nanoparticles with pure monoclinic (m) or tetragonal (t) crystal phase, three nickel catalysts (Ni/m‐ZrO2, Ni/t‐ZrO2 and Ni/m‐ZrO2 @Al2 O3 ) have been synthesized for CO2 reforming of methane. The Ni/t‐ZrO2 catalyst exhibited the lowest reforming activity with CH4 conversion of 15.5% at 700 °C under 1 atm with a gas hourly space velocity of 96 000 mL (h gcat) −1 . The Ni/m‐ZrO2 catalyst showed much higher initial activity but underwent severe deactivation, during which CH4 conversion decreased from 56.1% to 33.4% after 300 min of reaction. The nanocomposite Ni/m‐ZrO2 @Al2 O3 catalyst with confinement effect exhibited the best activity and good stability. Specifically, its CH4 conversion decreased merely from 60.2% to 55.3% after 24 h of reaction. CONCLUSIONS: Structural characterizations demonstrate that limited specific surface area and weak metal–support interactions existed on the Ni/t‐ZrO2 catalyst, which led to large nickel nanoparticles and thus poor reforming activity. Both Ni/m‐ZrO2 and Ni/m‐ZrO2 @Al2 O3 catalysts had high specific surface area and very small nickel nanoparticles, which may rationalize the high reforming activity. The improved stability of the Ni/m‐ZrO2 @Al2 O3 catalyst was mainly related to the alleviated carbon deposition resulting from enriched surface basicity and strengthened metal–support interactions. © 2020 Society of Chemical Industry (SCI)