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Auto-thermal reforming (ATR) of acetic acid (HAc) offers a feasible, carbon-neutral way to produce hydrogen, and Ni-based catalysts were found effective in ATR, while catalytic deactivation by sintering and carbon deposition needs to be addressed. Therefore, novel Mn-doped NiTiO3 catalysts were prepared by evaporation induced self-assembly method and tested in ATR; characterizations were used to explore the internal catalytic relationship between the carrier and active metals. The experimental results indicated the NiTiO3 catalyst doped with 10 wt.% of MnO exhibited the highest activity and enhanced stability: the conversion of HAc was stable at 100% and the yield of hydrogen was recorded near 2.5 mol-H2/mol-HAc. The characterization results showed that the NiTiO3 catalyst presented the highest specific surface area at 7.5 m2/g. After reduction and activation, NiTiO3 was transformed into Ni0, while Mn replaced Ni in NiTiO3 and formed a stable phase of MnTiO3 perovskite, which presented confinement effect on Ni0, preventing migration of Ni0 at high temperature with a relatively stable particle size within 41.6-44.5nm. These MnTiO3-supported nickel species effectively promoted the conversion of intermediate products such as CH3CO*, inhibited carbon deposition and improved hydrogen selectivity, showing application potential for hydrogen production via ATR of HAc. [ABSTRACT FROM AUTHOR]

The x%Ni/Sm2O3-MnO (x = 0, 10, 15, 20) catalysts derived from SmMn2O5 mullite were prepared by solution combustion and impregnation method; auto-thermal reforming (ATR) of acetic acid (HAc) for hydrogen production was used to explore the metal-support effect induced by Ni loadings on the catalytic reforming activity and product distribution. The 15%Ni/Sm2O3-MnO catalyst exhibited optimal catalytic performance, which can be due to the appropriate Ni loading inducing a strong metal–support interaction to form a stable Ni/Sm2O3-MnO active center, while side reactions, such as methanation and ketonization, were well suppressed. According to characterizations, Sm2O3-MnO mixed oxides derived from SmMn2O5 mullite were formed with oxygen vacancies; nevertheless, loading of Ni metal further promoted the formation of oxygen vacancies, thus enhancing adsorption and activation of oxygen-containing intermediate species and resulting in higher reactivity with HAc conversion near 100% and hydrogen yield at 2.62 mol-H2/mol-HAc. [ABSTRACT FROM AUTHOR]

Hydrogen, as a promising energy carrier, can be extracted from renewable biomass derived acetic acid (HAc). Ni-based catalysts supported on solid solution of Sm2−xPrxO3±δ were prepared using a coprecipitation method and evaluated in auto-thermal reforming (ATR) of HAc for hydrogen production. The results revealed that Pr species infiltrated the Sm2O3 lattice and formed a solid solution structure with oxygen vacancy defects, in which the redox process of Sm3+ + Pr3+ Sm2+ + Pr4+ enhanced oxygen mobility, facilitating gasification of the coking precursor and suppressing carbon deposition. DFT analysis also confirmed that Pr doping into the Sm2−xPrxO3±δ solid solution significantly lowered the energy barrier by 112 kJ mol−1 for formation of oxygen vacancies. Additionally, the interaction between Ni0 and Sm2−xPrxO3±δ effectively improved the dispersion of Ni0 metal particles, inhibiting sintering of Ni species. Consequently, the NSP10 catalyst (Ni0.80Sm1.72Pr0.24O3.74±δ) exhibited outstanding catalytic performance for hydrogen production: the conversion of HAc approached 100%, while the hydrogen yield remained stable at 2.75 mol-H2/mol-HAc. [ABSTRACT FROM AUTHOR]

To obtain high yields of hydrogen, a series of ZrxPr1–xOy‐supported cobalt catalysts were synthesized by the sol‐gel method and tested in autothermal reforming (ATR) of acetic acid (HAc) derived from bio‐oil. X‐ray diffraction, nitrogen physisorption, H2‐temperature‐programmed reduction, and thermogravimetric analysis were conducted to investigate the factors affecting the activities of the catalysts. Over the Co‐Zr‐Pr‐O catalyst, a ZrxPr1–xOy solid solution was formed after calcination; meanwhile, the active component of Co0 was highly dispersed over the solid solution after reduction in hydrogen for 1 h at 700 °C. As a result, stable reactivity was recorded in the ATR process of HAc: the hydrogen yield reached 2.58 molH2molHAc-1 with near 100 % HAc conversion, while better resistance to coking was observed. [ABSTRACT FROM AUTHOR]