The pivotal role of bromine in FeMnKBr/YNa catalyst for CO2 hydrogenation to light olefins

Wenjie Cui; Yudong Xia; Peipei Zhang; Yajie Fu; Xue Ye; Jie Li; Li Tan

doi:10.1016/j.isci.2024.109621

The pivotal role of bromine in FeMnKBr/Y_Na catalyst for CO₂ hydrogenation to light olefins

iScience. 2024 Mar 28;27(5):109621. doi: 10.1016/j.isci.2024.109621. eCollection 2024 May 17.

Authors

Wenjie Cui¹, Yudong Xia¹, Peipei Zhang², Yajie Fu³, Xue Ye¹, Jie Li¹, Li Tan³

Affiliations

¹ School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, China.
² CNOOC Institute of Chemicals & Advanced Materials, Beijing 102209, China.
³ Fujian Key Laboratory of Electrochemical Energy Storage Materials, State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou 350108, China.

Abstract

Light olefins are key intermediates in the synthesis of petrochemicals, and the conversion of stabilized carbon dioxide to light olefins using catalysts containing halogenated elements such as chlorine is a major challenge. Building on previous reports emphasizing the toxic effects of halogen elements on catalysts, we present the synthesis of FeMnKBr/Y_Na catalysts. This involved the synthesis of the catalyst by melt permeation using Br-containing potassium salts, other metal nitrates and Y_Na zeolites. The catalyst performed well in converting syngas (H₂/CO₂ = 3) to light olefins with a selectivity of 56.2%, CO₂ conversion of 34.4%, and CO selectivity of 13.6%. Adding Br aids in reducing the Fe phase, boosts catalyst carburization, and produces more iron carbide species. It also moderately deposits carbon on the active center's surface, enhancing active phase dispersion. Br's electronegativity mitigates the influence of K, reducing catalyst's carbon-carbon coupling ability, leading to more low-carbon olefins generation.

Keywords: Applied chemistry; Catalysis; Physical chemistry.