Button[Test,
  NotebookApply[EvaluationNotebook[],
    TemplateBox[{RowBox[{"[", ToBoxes@SelectionPlaceholder[Species],
    "]"}]}, "chemical", Editable -> True, Selectable -> True],
    Placeholder]]

SetOptions[EvaluationNotebook[],
  StyleDefinitions ->
    Notebook[{Cell[
      StyleData[
        StyleDefinitions ->
        FrontEnd`FileName[{"Report"}, "StandardReport.nb",
        CharacterEncoding -> "UTF-8"]]],
      Cell[StyleData["chemical"], StyleMenuListing -> None,
        TagBoxOptions -> {SyntaxForm -> "symbol"},
        ShowStringCharacters -> False, ShowAutoStyles -> False,
        ZeroWidthTimes -> True, FontWeight -> Plain,
        FontFamily -> "Times",
        TemplateBoxOptions -> {DisplayFunction -> (RowBox[{#}] &),
        SyntaxForm -> "symbol"}]}]]