The effects of stepped sites and ruthenium adatom decoration on methanol dehydrogenation over platinum-based catalyst surfaces

A density functional theory study of methanol dehydrogenation over stepped Pt(2 1 1) surfaces without and with Ru modification was carried out to understand fuel catalytic reactions on Pt-based catalysts. Two main pathways of the CH3OH dehydrogenation were examined: the O–H pathway which was initiated by O–H bond scission to form the methoxy (CH3O) intermediate followed by sequential cleavage of C–H bonds to CO, and the C–H pathway which was initiated by C–H bond scission to form the hydroxymethyl (CH2OH) followed by two C–H bond cleavages to COH and then CO. Possible crossover reactions between the O–H and C–H pathways were also computed. Compared to flat Pt(1 1 1), stepped Pt(2 1 1) increases the adsorption energies of intermediates, making no significant contribution to decreasing the reaction barriers of most elementary steps involved, except in the first hydrogen scission. However, on the Ru-modified surface, a significant reduction was found in reaction barriers for the first step of the C–H bond scission and a number of further dehydrogenation steps crossing over to the O–H pathway, with the most facile paths identified. Our data reveals the complexity of methanol catalytic reaction processes at the atomic level and contributes to a fundamental understanding of fuel reactions on Pt-based catalysts.

Renaissance Humanism and Ethnicity before Race:The Irish and the English in the Seventeenth Century

Inspired both by debates about the origins of the modern ideology of race and also by controversy over the place of Ireland and the Irish in theories of empire in the early modern Atlantic world, Renaissance Humanism and Ethnicity before Race argues that ethnic discourse among the elite in early modern Ireland was grounded firmly in the Renaissance Humanism and Aristotelianism which dominated all the European universities before the Enlightenment. Irish and English, Catholic and Protestant, all employed theories of human society based on Aristotle’s Politics and the natural law of the medieval universities to construct or dismantle the categories of civility and barbarism. The elites operating in Ireland also shared common resources, taught in the universities, for arguing about the human body and its ability to transmit hereditary characteristics. Both in Ireland and elsewhere in Europe, these theories of human society and the human body underwent violent changes in the late seventeenth century under the impact of the early Enlightenment. These changes were vital to the development of race as we know it.

Desegregation and Place Restructuring in the New Belfast

A sustained reduction in unemployment, economic growth and house price increase have reflected Belfast’s post-conflict renaissance just as readily as the global recession has exposed the fragility of construction-led growth. Rates of segregation had stabilised and new consumption spaces and élite developments further reflected the city’s engagement with globalisation and economic liberalisation. This paper explores the spatial impact of these processes, not least as gentrification has created new layers of residential segregation in a city already preoccupied with high rates of ethno-religious territoriality. A case study of south Belfast connects these shifts to the production of new mixed-religion neighbourhoods. These have the capacity to reduce the relevance of traditional binary identities, but at the same time reproduce new forms of segregation centred on tenure and class. The paper concludes by highlighting the implications for policy and practice, not least as the recession opens new spaces to present alternatives to the market logic.