Thomas Turner Pat O'connor

Bio: Thomas Turner Pat O'connor is an academic researcher from University of Limerick. The author has contributed to research in topics: Carbonization & Redress. The author has an hindex of 2, co-authored 2 publications receiving 41 citations.

Pd clusters supported on amorphous, low-porosity carbon spheres for hydrogen production from formic acid.

Abstract: Amorphous, low-porosity carbon spheres on the order of a few micrometers in size were prepared by carbonization of squalane (C30H62) in supercritical CO2 at 823 K. The spheres were characterized and used as catalysts’ supports for Pd. Near-edge X-ray absorption fine structure studies of the spheres revealed sp2 and sp3 hybridized carbon. To activate carbons for interaction with a metal precursor, often oxidative treatment of a support is needed. We showed that boiling of the obtained spheres in 28 wt % HNO3 did not affect the shape and bulk structure of the spheres, but led to creation of a considerable amount of surface oxygen-containing functional groups and increase of the content of sp2 hybridized carbon on the surface. This carbon was seen by scanning transmission electron microscopy in the form of waving graphene flakes. The H/C atomic ratio in the spheres was relatively high (0.4) and did not change with the HNO3 treatment. Palladium was deposited by impregnation with Pd acetate followed by reducti...

Women in the Zambian civil service: A case of equal opportunities?

Abstract: There is a paucity of empirical microlevel studies of women in the formal sector in developing countries. This article attempts to redress this deficit and focuses on the position of women in the Zambian civil service using information from a sample of personnel records. Although women are disproportionately represented in the civil service compared with other areas of the formal economy, the current positions of males and females are significantly different. However, the results of the survey are not easily encompassed in prevailing theoretical frameworks and, rather surprisingly, it appears that it is age rather than gender that is the crucial explanatory variable. Finally, a number of possible explanations are advanced to account for our findings.

Single Isolated Pd2+ Cations Supported on N-Doped Carbon as Active Sites for Hydrogen Production from Formic Acid Decomposition

Abstract: Single-site heterogeneous catalysis with isolated Pd atoms was reported earlier, mainly for oxidation reactions and for Pd catalysts supported on oxide surfaces. In the present work, we show that single Pd atoms on nitrogen-functionalized mesoporous carbon, observed by aberration-corrected scanning transmission electron microscopy (ac STEM), contribute significantly to the catalytic activity for hydrogen production from vapor-phase formic acid decomposition, providing an increase by 2–3 times in comparison to Pd catalysts supported on nitrogen-free carbon or unsupported Pd powder. Some gain in selectivity was also achieved. According to X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) studies after ex situ reduction in hydrogen at 573 K, these species exist in a Pd2+ state coordinated by nitrogen species of the support. Extended density functional theory (DFT) calculations confirm that an isolated Pd atom can be the active site for the reaction, giving decompos...

Anchoring IrPdAu Nanoparticles on NH2-SBA-15 for Fast Hydrogen Production from Formic Acid at Room Temperature.

Abstract: Hydrogen (H2), a regenerable and promising energy carrier, acts as an essential role in the construction of a sustainable energy system. Formic acid (HCOOH, FA), a natural biological metabolic products and also accessible through carbon dioxide (CO2) reduction, has a great potential to serve as a prospective H2 supplier for the fuel cell. Herein, ultrafine and electron-rich IrPdAu alloy nanoparticles with a size of 1.4 nm are highly dispersed on amine-modified mesoporous SiO2 (NH2-SBA-15) and used as a highly active and selective catalyst for fast H2 production from FA. The as-synthesized IrPdAu/NH2-SBA-15 possesses superior catalytic activity and 100% H2 selectivity with initial turnover frequency values of 6316 h-1 with the additive of sodium formate (SF) and 4737 h-1 even without SF at 298 K, comparable to the most effective heterogeneous catalysts ever published. The excellent performance of IrPdAu/NH2-SBA-15 was not only ascribed to the combination of the electronic synergistic effect of trimetallic alloys and the strong metal-support interaction effect but also attributed to the amine (-NH2) alkaline groups grafted on SBA-15, which is beneficial to boost the split of the O-H bond of FA.

African women in leadership: Current knowledge and a framework for future studies

Abstract: While the empirical literature on leadership and management in Africa is sparse, the literature on African women in leadership is even sparser. This article offers a critical examination of the current state of knowledge on African women in leadership and management. It draws from an extensive review of existing published research to summarise what has been studied and is currently known about their status, leadership styles, and the influence of gender on their experiences as leaders and managers. Based on this review, an integrative framework, drawing from African feminism and postcolonial theory, is proposed to advance the study of African women in leadership and management.

Highly Stable Single-Atom Catalyst with Ionic Pd Active Sites Supported on N-Doped Carbon Nanotubes for Formic Acid Decomposition.

Abstract: Single-atom catalysts with ionic Pd active sites supported on nitrogen-doped carbon nanotubes have been synthesized with a palladium content of 0.2-0.5 wt %. The Pd sites exhibited unexpectedly high stability up to 500 °C in a hydrogen atmosphere which was explained by coordination of the Pd ions by nitrogen-containing fragments of graphene layers. The active sites showed a high rate of gas-phase formic acid decomposition yielding hydrogen. An increase in Pd content was accompanied by the formation of metallic nanoparticles with a size of 1.2-1.4 nm and by a decrease in the catalytic activity. The high stability of the single-atom Pd sites opens possibilities for using such catalysts in high-temperature reactions.

Depositing CdS nanoclusters on carbon-modified NaYF4:Yb,Tm upconversion nanocrystals for NIR-light enhanced photocatalysis

Abstract: High-quality hexagonal NaYF4:Yb,Tm upconversion nanocrystals (UCNs) prepared in organic solutions display uniform sizes and strong UC emissions, but they possess a hydrophobic surface which hinders combining them with various semiconductor nanocrystals (NCs) to form a hybrid NIR-activated photocatalyst. Herein we present a facile approach to modify hydrophobic UCNs with a uniform carbon layer and enable them with hydrophilicity and surface functionalization. The carbon shell provides a good substrate for enriching with metal ions and in situ generation of CdS nanoclusters on the particle surface which can utilize both the upconverted UV and visible emissions. The developed NaYF4:Yb,Tm@C@CdS nanoparticles are characterized with TEM, SEM, XRD, PL and UV-Vis spectra and their formation mechanism is elucidated. The products display good photocatalytic activity under visible light and obviously enhanced performance under Vis-NIR light, due to the efficient utilization of UC emissions and the strong adsorption capacity of the carbon shell. The working mechanism of the hybrid photocatalysts is also proposed.