Mohamed A. Ebiad

Ni supported high surface area CeO2–ZrO2 catalysts for hydrogen production from ethanol steam reforming

The catalytic activity of nano-sized x%Ni/Ce0.74Zr0.26O2 (x = 0, 2, 10 and 20wt%) catalysts have been investigated to develop highly active catalysts for ethanol steam reforming (ESR) into hydrogen. The structure and surface properties of the catalysts were tested by XRD, TPR, HRTEM and BET surface areas. The effect of reaction temperature from 200 °C to 600 °C was studied in a flow system at atmospheric pressure with an ethanol/water molar ratio of 1 : 8. Selectivity was calculated for the catalytic products H2, CO, CO2 and CH4, as well as the intermediates C2H6, C2H4, C3H8, CH3CHO and CH3COCH3, at different reaction temperatures. It was found that complete conversion of ethanol with considerable amounts of H2 was obtained at 400 °C over all catalysts. H2 was produced at a very low temperature (200 °C) over 10% and 20% Ni loadings, while a maximum H2 selectivity (75%) is reached at 600 °C over the 2%Ni/Ce0.74Zr0.26O2 catalyst; this is most likely due to the small nickel particle size (2–4 nm) in 2%Ni, which results in enhancement of the metal–support interactions. Thermal decomposition of ethanol in an ethanol/water mixture under the same reaction conditions, but in the absence of catalyst, was also studied. HRTEM of the spent catalyst (8 h ESR) shows the deposition of carbon in the form of carbon nanotubes (CNTs).

Highly stable nano Ce–La catalyst for hydrogen production from bio-ethanol

The catalytic activity of a metal free nano particle, whose size ranged from 1–10 nm, was studied according to HRTEM and DLS results. The effect of reaction temperature (300–600 °C) on the catalytic activity of the prepared catalysts was studied in a flow system under atmospheric pressure with an ethanol–water molar ratio of 1 : 10. Selectivity was calculated for the products H2, CO, CO2 and CH4, as well as the intermediates C2H6, C2H4, CH3CHO and CH3COCH3, at different reaction temperatures. It was found that the addition of La increased the activity and stability of the Ce catalyst. H2 was produced at the lowest temperature (300 °C) over Ce–La0.2 & Ce–La0.5 catalysts. Complete conversion of ethanol with high hydrogen selectivity was obtained at 500 °C over Ce–La0.2 catalysts. Further increases of La content lead to decrease in the catalyst activity in accordance with the decrease of surface area to 9.6 m2 g−1. To study the stability of the prepared catalyst, the ESR reactions of Ce–La0.2 and Ce–La1 catalysts were investigated at 500 °C for 15 h. It was found that the Ce–La0.2 catalyst is more stable than the Ce–La1 catalyst over entire 15 h. Finally, we can say that lanthanum oxide (La2O3) is particularly suitable as a modifier due to its effectiveness in the prevention of sintering and improvement of thermal resistance at high temperatures. This oxide is also able to gasify the coke through the formation of La2O2CO3 oxy-carbonate.

Enhancement of hydrogen production via hydrogen peroxide as an oxidant

The performance of different Ni/Ce1−xZrxO2 (ss) catalysts of varying composition (x = 0, 0.12, 0.18 and 0.26) were investigated for hydrogen production by ethanol steam reforming (ESR). All catalysts were prepared by co-precipitation method and characterized for their surface area, pore volume, structure and morphology using different techniques (N2-BET, XRD and HRTEM). The Ce4+/Ce3+ redox couple in ceria-containing catalysts is known to be responsible for the OSC of these materials, so, the redox behaviors of these materials were investigated by EPR. Reaction parameters were optimized by varying steam to ethanol molar ratio (6, 8 and 10) in order to produce hydrogen with low carbon monoxide formation as low as possible. The minimum amounts of CO and carbon deposited are observed over Ni/CeZr-8 catalyst at 1:10 ethanol–water ratios. The obtained data are compared with data obtained from oxidative steam reforming of ethanol (OSRE) using hydrogen peroxide as an oxidant. The activity data indicated that hydrogen peroxide is an effective oxidant for OSRE over Ni/Ce1−xZrxO2 catalysts due to its ability to suppress CO formation and increase H2/CO ratio.

Mobility and Fate of Pollutants in the Aquifer System of the Northwestern Suez Gulf, Egypt

The northwestern part of Suez Gulf region is a strategic area in Egypt. It includes important sources of national income. To achieve the development goals, the government has established huge projects in this area (e.g. establishment and expanding of a large commercial port at Ain Sokhna, many industrial zones as well as tourism projects). The utilization of the Suez Gulf resources and their continuing development mainly depend on the creation of actual pollution control programs. The environmental quality control and pollution reduction activities are important ingredients of any economic development program. These different activities in this area depend mainly on the groundwater that is pumped intensively from different water bearing formations or aquifers. The main objective of the present work is compiling the previous studies from the 1980s up to 2015. These studies are concerned with estimating the concentrations of different pollutants in various ecosystems in the northwestern Suez Gulf region. Also, to provide an explanation for the movement of different pollutants such as organic and heavy metals from contaminated land to ground and surface (Gulf) waters. This issue has not been extensively surveyed before, and this review, gives specific directions for future monitoring and remediation strategies in this region.