인문학
사회과학
자연과학
공학
의약학
농수해양학
예술체육학
복합학
DBpia AI
AI 에이전트
AI 아이디어
AI 리더
AI 뷰어
Citeasy
크롬 서지관리 다운로드
지원사업
학술연구/단체지원/교육 등 연구자 활동을 지속하도록 DBpia가 지원하고 있어요.
커뮤니티
연구자들이 자신의 연구와 전문성을 널리 알리고, 새로운 협력의 기회를 만들 수 있는 네트워킹 공간이에요.
초록·키워드
Platinum catalysts supported on γ-Al<sub>2</sub>O<sub>3</sub> are central to a variety of applications. The conditions controlling the formation of Pt single atoms and subnanometric clusters remain elusive. The present work, based on surface organometallic chemistry (SOMC), unravels their formation under oxidative and reductive atmospheres. Following the grafting of MeCpPtMe<sub>3</sub> as a molecular precursor to generate highly dispersed sites on alumina, the evolution upon thermal treatment under oxidative or reductive conditions is monitored by <i>in situ</i> FTIR, with the ultimate goal to access catalysts with different single atom-to-cluster ratios, comparing SOMC with a conventional preparation method. Under oxidative conditions, all ligands are removed to form CO<sub>2</sub> in a multi-step process, while under reductive conditions, ligands likely decompose through hydrogenolysis/hydrogenation reactions. HAADF-STEM characterization and CO adsorption experiments reveal the presence of several states of Pt, depending on the Pt surface density and the treatment applied. Under a reductive atmosphere, the size of platinum clusters remains relatively constant and lower than 0.8 nm, regardless of the Pt surface density (0.03-0.09-0.15 Pt nm<sup>-2</sup>). Under an oxidative atmosphere, the Pt surface density is a key factor that drives the size of platinum clusters and the relative amount of single atoms, both of which are significantly different from those of a reference conventional catalyst obtained by incipient wetness impregnation of Pt(NH<sub>3</sub>)<sub>4</sub>(NO<sub>3</sub>)<sub>2</sub>. Notably, the material at 0.03 Pt nm<sup>-2</sup> exhibits mainly Pt single atoms after calcination, while increasing Pt density favors cluster formation.
인공지능 문자 인식 모델을 통해 추출된 텍스트로, 일부 오타나 오류가 포함될 수 있으나 지속적으로 개선 중입니다.
오류를 발견하셨다면 해당 부분을 드래그한 후 ' 를 통해 신고해주세요.
오류를 발견하셨다면 해당 부분을 드래그한 후 ' 를 통해 신고해주세요.
최근 본 자료 전체보기
