TY - JOUR
T1 - Hollow AMn2O4-δ (A = Co, Zn, Ni) nanotube for direct photo-oxidation of methane to C1 and C2 alcohols at atmospheric pressure and room temperature
AU - Duan, Jun
AU - Fan, Shiying
AU - Li, Xinyong
AU - Wang, Jing
AU - Bai, Chunpeng
AU - Yu, Shixuan
AU - Ling, Weitong
AU - Tian, Rui
AU - Zhang, Dongke
N1 - Publisher Copyright:
© 2024 Elsevier B.V.
PY - 2024/4/1
Y1 - 2024/4/1
N2 - Methane (CH4) conversion is brought into research hotspot in the field of environment, and direct photo-oxidation of methane into C1 and C2 alcohols under moderate conditions remains a huge challenge. Herein, we report a series of hollow AMn2O4-δ (A = Co, Zn, Ni) spinel nanotubes (HNTs) for the direct photo-oxidation of methane (DPOM) reaction. The results of catalytic performance demonstrated that the CH4 conversion and the yields of high value-added liquid products arrange in order of ZnMn2O4-δ HNTs > CoMn2O4-δ HNTs > NiMn2O4-δ HNTs. The ZnMn2O4-δ HNTs exhibited a superior CH4 conversion of 53.9 %, a liquid product yield of 241.7 μmol g−1h−1 (CH3OH 40.1 μmol g−1h−1, CH3CH2OH 200.9 μmol g−1h−1) and a selectivity of 100 % under light irradiation at atmospheric pressure and room temperature conditions. Xray photoelectron spectroscopy (XPS) and low-temperature electron paramagnetic resonance (EPR) analysis showed that the substitution of Zn ion at the A-site of manganate spinel significantly improved surface chemisorbed oxygen (Oα) and oxygen vacancy activity, which were beneficial to the formation of •CH3. Multi-technology photocatalytic activity characterizations results showed that ZnMn2O4-δ HNTs possessed a narrower band gap and greatly favored the separation of photogenerated carriers. Moreover, the DPOM reaction mechanism involving the formation and dehydrogenation of alkyl and alkoxy intermediates was proposed over AMn2O4-δ (A = Zn, Co, Ni) HNTs, which was investigated through temperature-programmed desorption of CH4 (CH4-TPD), in situ EPR, in situ Fourier transform infrared spectroscopy (FT-IR) and density functional theoretical (DFT) calculations. It emphasized that CH3OH was formed via the combination of •CH3 and •OH. And it was more inclined to generate CH3CH2OH through the intermediates *CH2CH3/*CH3O. This study could broaden the avenue toward the application of manganese-based spinel in the direct photo-oxidation of methane into alcohols and offer a disparate perspective on the role of the substitution of metal ion at the A-site in enhancing the photocatalytic performance.
AB - Methane (CH4) conversion is brought into research hotspot in the field of environment, and direct photo-oxidation of methane into C1 and C2 alcohols under moderate conditions remains a huge challenge. Herein, we report a series of hollow AMn2O4-δ (A = Co, Zn, Ni) spinel nanotubes (HNTs) for the direct photo-oxidation of methane (DPOM) reaction. The results of catalytic performance demonstrated that the CH4 conversion and the yields of high value-added liquid products arrange in order of ZnMn2O4-δ HNTs > CoMn2O4-δ HNTs > NiMn2O4-δ HNTs. The ZnMn2O4-δ HNTs exhibited a superior CH4 conversion of 53.9 %, a liquid product yield of 241.7 μmol g−1h−1 (CH3OH 40.1 μmol g−1h−1, CH3CH2OH 200.9 μmol g−1h−1) and a selectivity of 100 % under light irradiation at atmospheric pressure and room temperature conditions. Xray photoelectron spectroscopy (XPS) and low-temperature electron paramagnetic resonance (EPR) analysis showed that the substitution of Zn ion at the A-site of manganate spinel significantly improved surface chemisorbed oxygen (Oα) and oxygen vacancy activity, which were beneficial to the formation of •CH3. Multi-technology photocatalytic activity characterizations results showed that ZnMn2O4-δ HNTs possessed a narrower band gap and greatly favored the separation of photogenerated carriers. Moreover, the DPOM reaction mechanism involving the formation and dehydrogenation of alkyl and alkoxy intermediates was proposed over AMn2O4-δ (A = Zn, Co, Ni) HNTs, which was investigated through temperature-programmed desorption of CH4 (CH4-TPD), in situ EPR, in situ Fourier transform infrared spectroscopy (FT-IR) and density functional theoretical (DFT) calculations. It emphasized that CH3OH was formed via the combination of •CH3 and •OH. And it was more inclined to generate CH3CH2OH through the intermediates *CH2CH3/*CH3O. This study could broaden the avenue toward the application of manganese-based spinel in the direct photo-oxidation of methane into alcohols and offer a disparate perspective on the role of the substitution of metal ion at the A-site in enhancing the photocatalytic performance.
KW - Atmospheric pressure and room temperature
KW - C1 and C2 alcohols
KW - Manganate spinel
KW - Methane direct photo-oxidation
UR - http://www.scopus.com/inward/record.url?scp=85186433614&partnerID=8YFLogxK
U2 - 10.1016/j.cej.2024.149904
DO - 10.1016/j.cej.2024.149904
M3 - Article
AN - SCOPUS:85186433614
SN - 1385-8947
VL - 485
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
M1 - 149904
ER -