TY - JOUR
T1 - Carbon nanotubes-supported Ru catalyst for the generation of CO x-free hydrogen from ammonia
AU - Yin, S. F.
AU - Xu, B. Q.
AU - Zhu, W. X.
AU - Ng, C. F.
AU - Zhou, X. P.
AU - AU, Chak Tong
N1 - Funding Information:
This work was supported by RGC, Hong Kong Special Administration Region (HKBU 2037/00P), and NSF, PR China (Grant: 20125310) at Tsinghua University. B.Q. Xu thanks the Croucher Foundation for a visitorship to HKBU. We also thank Prof. Wang Shuiju of Xiamen University for the HRTEM analysis.
PY - 2004/9/1
Y1 - 2004/9/1
N2 - In comparison to Ru catalysts supported on activated carbon (AC), MgO, Al2O3, and TiO2 under similar reaction conditions, Ru catalyst using carbon nanotubes as support (Ru/CNTs) was found to show high NH3 conversion for the generation of COx-free hydrogen from NH3. The modification of the catalyst with KOH leads to a significant improvement in activity, either in term of NH3 conversion or TOF. The Ru/CNTs catalyst prepared from acetone solvent is more active than that from water solvent, and the use of the former leads to an increase in Ru dispersion and a decrease in residual Cl concentration. The results of H2-TPD and HRTEM characterization disclosed that the excellent catalytic activity of Ru/CNTs could be ascribed to the high dispersion of Ru particles, and to the high graphitization and high purity of the CNTs material. The residual Cl originated from the RuCl3 precursor was found to be a strong inhibitor for the decomposition reaction. Once the residual Cl is in the form of KCl, it is difficult to remove. The results of N 2-TPD studies imply that the desorption of N2 is the rate-determining step, and the modification with KOH leads to a decrease in N2 desorption temperature and in apparent activation energy of NH3 decomposition over Ru/CNTs.
AB - In comparison to Ru catalysts supported on activated carbon (AC), MgO, Al2O3, and TiO2 under similar reaction conditions, Ru catalyst using carbon nanotubes as support (Ru/CNTs) was found to show high NH3 conversion for the generation of COx-free hydrogen from NH3. The modification of the catalyst with KOH leads to a significant improvement in activity, either in term of NH3 conversion or TOF. The Ru/CNTs catalyst prepared from acetone solvent is more active than that from water solvent, and the use of the former leads to an increase in Ru dispersion and a decrease in residual Cl concentration. The results of H2-TPD and HRTEM characterization disclosed that the excellent catalytic activity of Ru/CNTs could be ascribed to the high dispersion of Ru particles, and to the high graphitization and high purity of the CNTs material. The residual Cl originated from the RuCl3 precursor was found to be a strong inhibitor for the decomposition reaction. Once the residual Cl is in the form of KCl, it is difficult to remove. The results of N 2-TPD studies imply that the desorption of N2 is the rate-determining step, and the modification with KOH leads to a decrease in N2 desorption temperature and in apparent activation energy of NH3 decomposition over Ru/CNTs.
KW - Ammonia decomposition
KW - Carbon nanotubes
KW - Hydrogen manufacture
KW - Ruthenium catalyst
UR - http://www.scopus.com/inward/record.url?scp=4444279917&partnerID=8YFLogxK
U2 - 10.1016/j.cattod.2004.05.011
DO - 10.1016/j.cattod.2004.05.011
M3 - Conference article
AN - SCOPUS:4444279917
SN - 0920-5861
VL - 93-95
SP - 27
EP - 38
JO - Catalysis Today
JF - Catalysis Today
T2 - Selections from the Presentations of the 3rd Asia-Pacific Congress
Y2 - 12 October 2003 through 12 October 2003
ER -