Abstract

This study presents a sequential thermochemical catalytic process for converting CO2 into carbon nanotubes (CNTs), achieving nearly 99% overall CO2 conversion and solid carbon yields of up to 49% in a single pass. The overall transformation is divided into two thermodynamically favorable steps: (1) low-temperature CO2 methanation to CH4 over a sol-gel-prepared Ni87Ce6.5Zr6.5-SG catalyst, which achieved >95% CO2 conversion at 250 °C in a single pass, and (2) subsequent methane pyrolysis to CNTs and H2 over a Ni@Al2O3-IE core-shell catalyst, which showed improved stability and carbon yield compared with conventional catalysts. Catalyst characterization revealed the synergistic roles of Ce and Zr in the methanation catalyst and the importance of the core-shell architecture in suppressing deactivation during methane pyrolysis. This CH4-bridged strategy avoids intrinsic carbon loss through CO2 regeneration in CO-mediated routes, enabling high single-pass solid‑carbon yield in a gas-phase sequential process. The resulting product consists predominantly of structurally defined CNTs, which were further validated as functional additives in lithium-ion-battery-related systems. Overall, this work establishes an effective route for converting captured CO2 into value-added CNT materials.

Department(s)

Electrical and Computer Engineering

Second Department

Chemical and Biochemical Engineering

Publication Status

Open Access

Keywords and Phrases

CH4-bridged CO2 conversion; CO2 utilization; Sequential system; Solid carbon sequestration

International Standard Serial Number (ISSN)

1385-8947

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2026 Elsevier, All rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Publication Date

15 Jun 2026

Download

Full Text Link

Share

 
COinS