Ultrasound assisted co-precipitation of nanostructured CuO–ZnO–Al2O3 over HZSM-5: Effect of precursor and irradiation power on nanocatalyst properties and catalytic performance for direct syngas to DME

Abstract

Nanostructured CuO-ZnO-Al2O3/HZSM-5 was synthesized from nitrate and acetate precursors using ultrasound assisted co-precipitation method under different irradiation powers. The CuO-ZnO-Al2O3/HZSM-5 nanocatalysts were characterized using XRD, FESEM, BET, FTIR and EDX Dot-mapping analyses. The results indicated precursor type and irradiation power have significant influences on phase structure, morphology, surface area and functional groups. It was observed that the acetate formulated CuO-ZnO-Al2O3/HZSM-5 nanocatalyst have smaller CuO crystals with better dispersion and stronger interaction between components in comparison to nitrate based nanocatalysts. Ultrasound assisted co-precipitation synthesis method resulted in nanocatalyst with more uniform morphology compared to conventional method and increasing irradiation power yields smaller particles with better dispersion and higher surface area. Additionally the crystallinity of CuO is lower at high irradiation powers leading to stronger interaction between metal oxides. The nanocatalysts performance were tested at 200-300 °C, 10-40 bar and space velocity of 18,000-36,000 cm(3)/g h with the inlet gas composition of H2/CO = 2/1 in a stainless steel autoclave reactor. The acetate based nanocatalysts irradiated with higher levels of power exhibited better reactivity in terms of CO conversion and DME yield. While there is an optimal temperature for CO conversion and DME yield in direct synthesis of DME, CO conversion and DME yield both increase with the pressure increase. Furthermore ultrasound assisted co-precipitation method yields more stable CuO-ZnO-Al2O3/HZSM-5 nanocatalyst while conventional precipitated nanocatalyst lost their activity ca. 18% and 58% in terms of CO conversion and DME yield respectively in 24 h time on stream test.

Abatement of toluene from polluted air over Mn/Clinoptilolite–CeO2 nanopowder: Impregnation vs. ultrasound assisted synthesis with various Mn-loading

“…Among different methods for synthesis of nanostructure materials, sonochemistry due to its power to control size, morphology and especially distribution of active phase on the support in mixed phase, has been widely applied in nanomaterial synthesis [43][44][45][46]. Sonochemical synthesis method, under principle of acoustic cavitation, provides an ultimate condition, local temperature of 5000 K, and pressures of 2000 bar, heating and cooling rates of >10 10 K/s induce unique interaction between energy and matter [47][48][49][50].…”

Microwave, Ultrasound, and Mechanochemistry: Unconventional Tools that Are Used to Obtain “Smart” Catalysts for CO2 Hydrogenation

“…The effect of US irradiation power was evaluated on different CZA/HZSM-5 catalysts prepared by US-assisted co-precipitation method [92]. The results of a thorough physico-chemical characterization evidenced that the nature of the precursors and the time of irradiation strongly affected the morphology, the surface area, the functional groups, and the structure of the final materials.…”

The Preparation of 99mTc-MAG3 radiotracer by Ultrasound

“…Ultrasound waves cause cavitation phenomenon which generates enough energy to alter vibrational and rotational molecular states. The reactions under ultrasound waves can be leaded to better yields, faster rates and milder temperatures [15][16][17][18] . The new developed technique was examined to prepare the 99m TcSestamibi radiocomplex as an alternative and reliable method in clinical practice [19][20][21] .…”