TY - JOUR
T1 - Conversion of methane to acetonitrile over GaN catalysts derived from gallium nitrate hydrate co-pyrolyzed with melamine, melem, or g-C3N4
T2 - the influence of nitrogen precursors
AU - Trangwachirachai, Korawich
AU - Chen, Chin Han
AU - Huang, Ai Lin
AU - Lee, Jyh Fu
AU - Chen, Chi Liang
AU - Lin, Yu Chuan
N1 - Funding Information:
This study was supported by the Ministry of Science and Technology (Projects 109-2628-E-006-011-MY3, 110-2221-E-006-165-MY3, 110-2923-E-006-005-MY3, and 110-2927-I-006-506) and the Higher Education Sprout Project, Ministry of Education to the Headquarters of University Advancement at National Cheng Kung University (NCKU). The authors also appreciate the use of an elemental analyzer (EA000600, MOST 110-2731-M-006-001) belonging to the Core Facility Center of National Cheng Kung University.
Publisher Copyright:
This journal is © The Royal Society of Chemistry
PY - 2022/1/7
Y1 - 2022/1/7
N2 - Co-pyrolyzing gallium nitrate hydrate and melamine, melem, or g-C3N4 generates gallium nitride (GaN) for the conversion of methane to acetonitrile (AcCN). The solid-state-pyrolysis-made GaN catalysts exhibited better activity than commercial GaN. Among the as-prepared catalysts, GaN made by using g-C3N4 with a N/Ga ratio of 2 (i.e., GaN-(C3N4)-(2)) was the most attractive: a high initial methane conversion (28.2%), a high initial AcCN productivity (151 μmol gcat−1 min−1), and a 6 h accumulated AcCN yield (5816 μmol gcat−1) were obtained at 700 °C with a space time of 3000 mLCH4 gcat−1 h−1. GaN-(C3N4)-(2) had finely dispersed GaN crystals and enriched amorphous CN species (e.g., sp2 N and C N groups), and both are important in promoting the methane conversion rate. GaN agglomeration, coke deposition, and depleted CN species contributed to the deactivation of the catalyst, and a nitridation–activation process could rejuvenate the activity partially. The analysis of the structure–activity correlation revealed that the accumulated AcCN yield had an inverse trend with respect to the crystallite size of GaN and the sp3/sp2 ratio of the N environment.
AB - Co-pyrolyzing gallium nitrate hydrate and melamine, melem, or g-C3N4 generates gallium nitride (GaN) for the conversion of methane to acetonitrile (AcCN). The solid-state-pyrolysis-made GaN catalysts exhibited better activity than commercial GaN. Among the as-prepared catalysts, GaN made by using g-C3N4 with a N/Ga ratio of 2 (i.e., GaN-(C3N4)-(2)) was the most attractive: a high initial methane conversion (28.2%), a high initial AcCN productivity (151 μmol gcat−1 min−1), and a 6 h accumulated AcCN yield (5816 μmol gcat−1) were obtained at 700 °C with a space time of 3000 mLCH4 gcat−1 h−1. GaN-(C3N4)-(2) had finely dispersed GaN crystals and enriched amorphous CN species (e.g., sp2 N and C N groups), and both are important in promoting the methane conversion rate. GaN agglomeration, coke deposition, and depleted CN species contributed to the deactivation of the catalyst, and a nitridation–activation process could rejuvenate the activity partially. The analysis of the structure–activity correlation revealed that the accumulated AcCN yield had an inverse trend with respect to the crystallite size of GaN and the sp3/sp2 ratio of the N environment.
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U2 - 10.1039/d1cy01362a
DO - 10.1039/d1cy01362a
M3 - Article
AN - SCOPUS:85122652684
SN - 2044-4753
VL - 12
SP - 320
EP - 331
JO - Catalysis Science and Technology
JF - Catalysis Science and Technology
IS - 1
ER -