CO₂ Hydrogenation to Methanol via In‐situ Reduced Cu/ZnO Catalyst Prepared by Formic acid Assisted Grinding

Abstract

Methanol is an essential chemical raw material and potential alternative energy source. In this paper, Cu based catalyst was prepared by the noble solid phase grinding method for CO2 hydrogenation to methanol. The influence of chelating agent, heating rate, calcination temperature and calcination period of the precursor on catalyst performance were studied in depth. The catalyst precursor with formic acid as a chelating agent was reduced in‐situ when calcined in nitrogen (N2) at 573 K. The formic acid was decomposed, releasing the reducing agents, CO and H2, resulting in continuous in‐situ CuO reduction to metallic Cu0. XRD, XPS, BET, TG‐DSC, H2‐TPR and other characterization techniques were employed to analyze the catalyst properties. Results revealed that CuO was successfully reduced in‐situ to Cu0 during calcination process in a nitrogen atmosphere without further reduction. The catalyst prepared by formic acid grinding (F/I−Cu/ZnO) showed highest catalytic activity compared with the conventional catalyst which was further reduced by 5% H2 (F/H−Cu/ZnO). CO2 conversion and methanol selectivity reached 33.44% and 84.26%respectively.

LPG Direct Synthesis from Syngas over a Cu/ZnO/ZrO2/Al2O3@H‐β Zeolite Capsule Catalyst Prepared by a Facile Physical Method

“…As can be visibly noticed, the pattern of CZZA catalyst exhibited characteristic peaks of both CuO mainly as tenorite (JCPDS 48‐1548) and ZnO as zincite (JCPDS 36‐1451) . It was reported that an intrinsic association between CuO and ZnO species enhances particle dispersion, where ZnO species functions as spacers between metallic Cu particles inhibiting them from aggregation and sintering …”

“…The core CZZA metal catalyst somewhat possess a unique fabrication hinged on its excellent hydrogenation ability associated to Cu−Zn . This is further coupled to an escalated catalytic activity and a remarkable thermal stability, credited to the incorporated Al and Zr for an effective high magnitude intermediate product (methanol) formation .…”

Hydrogenation of Carbon Dioxide to Methanol over Non-Noble Catalysts: A State-of-the-Art Review

“…In Cu-based catalysts, the support with high specific surface area can disperse the active components well and prevent the catalyst from deactivation due to sintering [35]. The traditional supports primarily include Al 2 O 3 [56][57][58], ZnO [59,60], and ZrO 2 [61][62][63]. However, the water generated by the side reaction can accelerate the sintering of the active sites, which leads to the catalyst being relatively easy to deactivate, and Al 2 O 3 has hydrophilic properties, so the development of other carriers to make up for this is necessary.…”