acknowledgments in elsevier journal format

You should code it as an unnumbered section, i.e. section*{Acknowledgement}.

Source

This answer comes from a FAQ for elsarticle.cls. The FAQ is hosted by stmDOCS, which is connected to Elsevier in the following way.

Elsevier uses Neptune, which is 'a web-based proofing framework for LaTeX authors. It is part of TEXFolio, the complete journal production system in the cloud' (see here). In turn, TEXFolio is part of stmDOCS (see here).

Now, in the FAQ, under 'Main matter', we find question 7:

How can I create an acknowledgement section?

The answer, reproduced here, is

It should be coded as an unnumbered section. For example: <geshi lang="latex">

section*{Acknowledgement}

</geshi>

The geshi parts are presumably not part of the answer. GeSHi stands for 'Generic Syntax Highlighter' (as their website explains, 'As long as you have a language file for almost any computer language - whether it be a scripting language, object orientated, markup or anything in between - GeSHi can highlight it').