A bimetallic-MOF catalyst for efficient CO2 photoreduction from simulated flue gas to value-added formate. Issue 23 (4th June 2020)

• Record Type: Journal Article
• Authors: Guo, Shao-Hong; Qi, Xiang-Juan; Zhou, Hui-Min; Zhou, Jie; Wang, Xiao-Hui; Dong, Man; Zhao, Xue; Sun, Chun-Yi; Wang, Xin-Long; Su, Zhong-Min
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 23(2020)
• Page Start: 11712
• Page End: 11718
• Publication Date: 2020-06-04
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0ta00205d
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Bimetallic Ni/Mg-MOF-74 was reported as a catalyst for efficient CO2 photoreduction from simulated flue gas to generate value-added formate. Abstract : Direct CO2 conversion from flue gas into high-value products is of great significance not only in relieving environmental burden but alleviating the energy crisis by a low-cost and energy-saving avenue, yet few studies in this aspect have been reported. Herein, we report metal-node-dependent catalytic performance for solar-energy-powered CO2 reduction to formate in simulated flue gas by bimetallic Ni/Mg-MOF-74. The yield of HCOO − with Ni0.75 Mg0.25 -MOF-74 as a catalyst in pure CO2 is 0.64 mmol h −1 gMOF −1 which is higher than that of Ni-MOF-74 (0.29 mmol h −1 gMOF −1 ) and Ni0.87 Mg0.13 -MOF-74 (0.54 mmol h −1 gMOF −1 ), whereas monometallic Mg-MOF-74 is almost inactive, indicating that reactivity relies on metal nodes. In simulated flue gas without water vapor at 20 °C, ∼80% of the reactivity in pure CO2 is retained, with HCOO − generation reaching 0.52 mmol h −1 gMOF −1 . This activity is comparable to that of the best MOF catalysts in pure CO2, demonstrating that Ni/Mg-MOF-74 not only overcomes the limitation from CO2 concentration, but also has good resistance to other gas components in flue gas at 20 °C. DFT calculations reveal the high output for HCOO − from two crucial factors: strong CO2 binding affinity of Mg sites, and the synergistic effect of Mg and Ni leading to the stabilization of the key *OCOH intermediate with an appropriate energy barrier. This work paves a new route for double-metal MOFs to enhance the CO2 photoreduction reactivity in flue gas.