You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

ZnO is a CO(2)-selective steam reforming catalyst. ZnO was tested as possible methanol and - since formaldehyde is one of the key intermediates in methanol conversion reactions - also as formaldehyde steam reforming catalyst. Catalytic experiments in a batch as well as a flow reactor resulted in highly selective steam reforming, though at low specific activities, of formaldehyde and methanol over ZnO toward CO(2) (selectivity of 95-99.6%). Comparison of the behavior of ZnPd near-surface intermetallic phases, unsupported intermetallic ZnPd and supported ZnPd/ZnO catalysts reveals that formaldehyde is formed from methanol in parallel with CO(2) on the former, while on unsupported intermetallic ZnPd and ZnO-supported ZnPd, it is efficiently reacted toward CO(2), thus, a beneficial role of ZnO in oxidizing formaldehyde-derived intermediates toward CO(2) is evident.
{"Chemical": ["CO(2)", "formaldehyde", "methanol", "ZnO", "ZnPd"]}