Efficient Ni-based catalysts for low-temperature reverse water-gas shift (RWGS) reaction

Area of Science:

• Catalysis
• Materials Science
• Environmental Chemistry

Background:

• Carbon dioxide (CO2) emissions pose environmental challenges.
• CO2 hydrogenation to syngas offers economic benefits and CO2 utilization.
• Nickel-based catalysts show activity but require high temperatures (over 700°C).

Purpose of the Study:

• To develop efficient catalysts for CO2 hydrogenation at lower temperatures.
• To investigate the effect of copper addition to nickel catalysts.
• To optimize catalyst composition and reduction temperature for enhanced performance.

Main Methods:

• Synthesis and characterization of bimetallic Ni-Cu catalysts.
• Evaluation using H2-TPR, XRD, BET, in-situ XPS, and CO2-TPD techniques.
• Testing CO2 hydrogenation activity and CO selectivity at various conditions.

Main Results:

• Ni/Cu ratios significantly influenced CO2 hydrogenation activity and CO selectivity.
• Synergistic effects between Ni and Cu were observed in bimetallic catalysts.
• Catalyst reduction temperature impacted the number and dispersion of active species, affecting performance.
• The Ni1Cu1-400 catalyst demonstrated high CO selectivity (up to 90%) and stability at 400°C.
• A fast formation rate of 1.81×10^-5 mol/gcat/s was achieved.

Conclusions:

• Bimetallic Ni-Cu catalysts offer improved performance for CO2 hydrogenation compared to pure Ni catalysts.
• Optimized Ni/Cu ratio and reduction temperature are crucial for catalyst efficiency.
• The Ni1Cu1-400 catalyst shows significant potential for the reverse water-gas shift (RWGS) reaction at lower temperatures.